nokia gsm_edge feature description bsss10.5ed

GSM/EDGE Feature Description

dn00286056Issue 3-0 en

# Nokia CorporationNokia Proprietary and Confidential

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2003282-1.0S10.5 ED documentation set

The information in this document is subject to change without notice and describes only theproduct defined in the introduction of this documentation. This document is intended for the useof Nokia's customers only for the purposes of the agreement under which the document issubmitted, and no part of it may be reproduced or transmitted in any form or means without theprior written permission of Nokia. The document has been prepared to be used by professionaland properly trained personnel, and the customer assumes full responsibility when using it.Nokia welcomes customer comments as part of the process of continuous development andimprovement of the documentation.

The information or statements given in this document concerning the suitability, capacity, orperformance of the mentioned hardware or software products cannot be considered binding butshall be defined in the agreement made between Nokia and the customer. However, Nokia hasmade all reasonable efforts to ensure that the instructions contained in the document areadequate and free of material errors and omissions. Nokia will, if necessary, explain issueswhich may not be covered by the document.

Nokia's liability for any errors in the document is limited to the documentary correction of errors.NOKIA WILL NOT BE RESPONSIBLE IN ANY EVENT FOR ERRORS IN THIS DOCUMENTOR FOR ANY DAMAGES, INCIDENTAL OR CONSEQUENTIAL (INCLUDING MONETARYLOSSES), that might arise from the use of this document or the information in it.

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Other product names mentioned in this document may be trademarks of their respectivecompanies, and they are mentioned for identification purposes only.

Copyright © Nokia Corporation 2003. All rights reserved.

2 (266) # Nokia CorporationNokia Proprietary and Confidential



Contents

Contents 3

List of tables 8

List of figures 9

Summary of changes 11

1 Overview to GSM/EDGE Feature Description 15

2 Capacity and performance 172.1 GSM-WCDMA Inter-System Handover 172.2 BCFA card with 4 Mb flash and DRAM 192.3 BTS time base reference from PCM 192.4 BTS clock synchronisation 202.5 DE34/DF34 four-way wideband combining with dual duplexing 212.6 Four-way wideband combiner 222.7 Downlink diversity 222.8 FOC algorithm for 2nd generation BTS 232.9 Redundant cold stand-by TRX 232.10 Redundant/ floating TRX 242.11 Six sector support 252.12 Nokia MetroSite Base Station configurations 252.13 External interfaces of Nokia MetroSite Base Station 262.14 Nokia UltraSite GSM/EDGE Base Station configurations 282.15 External interfaces of Nokia UltraSite GSM/EDGE Base Station 302.16 Nokia InSite Base Station configurations 322.17 External interfaces of the Nokia InSite Base Station 332.18 BSC clock and tone generator 342.19 Call release after loss of TRAU frame synchronisation 352.20 Ciphering 362.21 Discontinuous reception (DRX) 372.22 Mode modify procedure 382.23 Nokia High Capacity Base Station Controller, BSC3i 382.24 Nokia Large Capacity Base Station Controller, BSC2E/A 402.25 Nokia High Capacity Base Station Controller, BSC2i 412.26 Dynamic SDCCH allocation 472.27 Half Rate 472.28 GSM/EDGE Dual Band 492.29 Intelligent Underlay-Overlay (IUO) 502.30 Frequency Hopping (FH) 522.31 Intelligent Frequency Hopping (IFH) 542.32 Double Mobile Allocation (MA) list amount 542.33 Flexible MAIO management 542.34 C/I Based Handover Candidate Evaluation 552.35 Radio Channel Allocation 562.36 GSM handover and power control algorithms 572.37 Traffic Reason Handover 59



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Contents

2.38 Directed Retry (DR) 592.39 FACCH call set-up due to SDCCH congestion 602.40 Discontinuous transmission downlink and uplink (DTX) 612.41 Advanced Multilayer Handling (AMH) 622.42 Dynamic Hotspot 662.43 Direct Access to Desired Layer/Band 682.44 Nokia Talk-family Base Station synchronisation 702.45 Nokia PrimeSite single branch combining 702.46 12-TRX cell with RTC dual duplexing 712.47 Variable DL Power Control 712.48 Mobile Station capability indication 722.49 Automated Planning 732.50 Synchronised Base Station Subsystem 762.51 FER Measurement 772.52 Adaptive Multi Rate Codec, AMR 782.53 Common BCCH Control 872.54 Dynamic Abis Allocation 882.55 Chaining of Nokia MetroSite Base Station 892.56 New MS power levels 902.57 Chained Cells in Rapid Field Drop 902.58 MS Speed Detection 912.59 Fast moving MS handling in macrocell 922.60 C2 microcell reselection 932.61 Multi BCF Control 932.62 Optimisation of the MS power level in handovers 942.63 High Capacity Signalling Links on A interface 95

3 Coverage 973.1 Enhanced Coverage by Frequency Hopping 973.2 Improved solution for Extended Cell 983.3 Intelligent Coverage Enhancement (ICE) 983.4 Mast Head Preamplifier 1013.5 Receiver diversity 1023.6 TRX transmit booster unit 1023.7 GSM/EDGE 800 103

4 Data � IP Multimedia 1054.1 High Speed Circuit Switched Data (HSCSD) 1054.2 Data services 1064.3 GPRS functionality 1084.4 GPRS in Nokia Base Stations 1124.5 Optimised GPRS Radio Resource Management 1124.6 Cell selection and re-selection 1144.7 Power control 1144.8 Coding Scheme (CS) selection 1154.9 GPRS radio network parameters and parameter management 1154.10 Frame Relay and Gb Interface 1164.11 Packet Control Unit (PCU) hardware in BSC 1174.12 Enhanced Data Rates for Global Evolution, EDGE 1184.13 Nokia Smart Radio Concept for EDGE (Nokia SRC) 1214.14 Support of PCCCH/PBCCH 122




4.15 Priority Class based Quality of Service 1234.16 System Level Trace 125

5 Operability 1275.1 Rx antenna supervision by comparing RSSI value 1275.2 TRX monitoring by RSSI 1285.3 Redundant BTS station unit 1285.4 Double BCCH allocation list 1285.5 Undefined adjacent cell measurements 1295.6 Flow control 1305.7 BSC hardware configuration management 1315.8 BSC MML authorisation 1325.9 BSC software configuration management 1335.10 BTS hardware database management 1355.11 BTS local user interface - BTS MMI 1365.12 BTS software package management 1375.13 Command calendar 1385.14 Command file 1395.15 External Battery Back Up unit support 1395.16 Forced handover for O&M reason 1405.17 Frequency plan changing 1405.18 Intelligent BTS shutdown due to mains break 1415.19 Online BTS software loading 1425.20 Radio network configuration management 1435.21 Radio network fault recovery 1455.22 Remote BTS MMI 1455.23 Safecopying of files 1465.24 Security reporting 1475.25 Serial and version number storage 1475.26 Transcoder configuration management 1485.27 Transcoder software downloading 1485.28 Alarm if number of usable A-If circuits below limit 1495.29 BCCH supervision 1505.30 BSC external alarms and controls 1505.31 BSC system maintenance 1505.32 BTS-TC connection establishment supervision 1545.33 BTS external alarms and controls 1555.34 BTS testing in BSC 1565.35 GSM trace 1625.36 Hot spot location 1645.37 PM file compression 1645.38 Radio network maintenance 1645.39 TX antenna VSWR supervision 1675.40 Radio network supervision 1675.41 C/I ratio statistics (C/I) 1685.42 CCCH load statistics 1695.43 Administration of measurements and observations 1705.44 Handover adjacent cell measurements 1725.45 MS speed detection measurement 1735.46 Underlay-overlay statistics measurements 1735.47 Radio network optimisation measurements 173



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Contents

5.48 RX quality statistics per TRX 1755.49 Traffic distribution per site (Dual Band measurements) 1755.50 Standard measurements 1765.51 Online observation 1835.52 BSC observations 1845.53 Signalling point code modification 1875.54 TCSM2 routine tests of A-if circuits 1875.55 Transmission equipment alarm handling 1885.56 Trace window for dropped calls 1885.57 SCCP improvement 1895.58 Real time update to Base Station 1905.59 Runtime diagnostics and BTS alarms 1905.60 BTS temperature control 1915.61 Nokia Base Station resets 1935.62 Autodetection of site configuration 1945.63 BTS supervision 1965.64 Automatic picocell planning 1985.65 Channel Finder 1995.66 Nokia autoconfiguration in the Nokia GSM Office Solution 2015.67 Power system management 2025.68 Nokia Power System Management (PSM) Enhancements 2045.69 Remote BTS manager for UltraSite and MetroSite 2045.70 PrimeSite TRX ID from BSC 2055.71 Clock synchronisation between Nokia UltraSite and Talk-family Base

Stations 2065.72 Training Sequence Code (TSC) vs. BTS Colour Code (BCC) 207

6 Transmission 2096.1 Trunk network maintenance 2096.2 Ater trunk transmission allocation 2106.3 Redundant Ater (or A) trunk 2106.4 Abis trunk signalling 2106.5 Redundant Abis trunk 2116.6 ISDN Abis (ETSI) 2116.7 Abis transmission by HDSL 2126.8 Satellite Abis 2126.9 Abis trunk transmission allocation 2136.10 T1 Abis (ANSI) BTS 2136.11 TRU manager 2136.12 Supervision of transmission equipment 2146.13 Q1 interface between the BSC and transmission equipment 2156.14 Wired alarm collection at transmission equipment site 2156.15 Remote use of node managers of Nokia NetAct at Nokia NetAct site 2156.16 Remote transmission equipment management 2166.17 Local transmission equipment management 2176.18 Nokia GSM Office transmission operability 2186.19 Supervision of Nokia GSM Office transmission units 2196.20 Support for Nokia microwave radio links 2196.21 Transmission operability 2206.22 Supervision of transmission units 2216.23 Synchronisation 222




6.24 Duplicated transmission card 2236.25 Combined O&M and telecom signalling 2236.26 Ater trunk transmission allocation 224

7 Services 2257.1 Tandem Free Operation (TFO) 2257.2 Noise Suppression 2277.3 Support for Noise Suppression (NS) and Dual Rate Codec (DR) in the

same pool 2287.4 Queuing 2287.5 Queuing and priority 2297.6 Acoustic Echo Cancellation (AEC) 2307.7 IDR and TR as per PIE (Priority Information Element) 2317.8 Trunk reservation 2317.9 Intelligent Directed Retry 2327.10 Fixed level adjustment 2337.11 Soft comfort noise 2337.12 Handling of frames received with errors (handover improvement) 2347.13 Bad frame handling improvement (poor field improvement) 2347.14 Adaptive gain control/downlink 2347.15 ETR 09.90 compliance 2357.16 SMS-CB DRX 2357.17 SMS point-to-point 2367.18 Enhanced Full Rate Codec (ETSI) 2377.19 Enhanced Full Rate Codec (ANSI) 2397.20 Cell Broadcast 2407.21 Cell broadcast interface to cell broadcast centre 2417.22 Nokia mPosition" Solution 2427.23 Wireless Priority Service in BSC 2467.24 Text Telephony (TTY) 247

8 BSS10, BSS10.5 and BSS10.5 ED dependencies 249



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Contents

List of tables

Table 1. 37

Table 2. Channel and speech codec modes for AMR 79

Table 3. Number of LapD links and CCS7 links per BCSU with or without Highcapacity CCS7 link for high capacity BSC 95

Table 4. Peak data rates for single slot EGPRS 120




List of figures

Figure 1. GSM-WCDMA RAN network architecture 18

Figure 2. Nokia UltraSite GSM/EDGE Base Station Indoor 29

Figure 3. Nokia UltraSite GSM/EDGE Base Station Outdoor 30

Figure 4. Nokia InSite Base Station 33

Figure 5. BSC3i 40

Figure 6. BSC2i 42

Figure 7. Tri band Common BCCH 87

Figure 8. Segment in Common BCCH 88

Figure 9. Segment in Multi BCF Control 94

Figure 10. GPRS network 109

Figure 11. EDGE builds on the existing GSM network 119

Figure 12. Support of PCCCH/PBCCH 123

Figure 13. Trace activation/deactivation and report generation 125



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List of figures

Summary of changes

Summary of changes

Changes between document issues are cumulative. Therefore, the latest documentissue contains all changes made to previous issues.

Changes made between issues 2 and 3

Dual band 800/1800

Information on 800/1800 frequencies added

Gb over IP

Information on Gb over IP feature removed.

EGPRS MCS-1...MCS-9

Information added.

WPS

Information on the new feature added.

Text Telephony

Dependency table of the feature added.

Priority Class based Quality of Service

Text modified.

System Level Trace

Text modified.

AMR

Modification made on the note of the table.

Nokia mPosition" release 2 for E-OTD phones

Title changed to Nokia mPosition" Solution. Text updated to S10.5 ED level.



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Summary of changes

Nokia mCatch" rel1.0 Location Services for Legacy Phones

Chapter removed. Information included in chapter Nokia mPosition" Solution.

Nokia Power System Management (PSM) Enhancements

Chapter added.

Remote BTS manager for UltraSite and MetroSite

Chapter added.

Changes made between issues 1 and 2

Gb over IP

Feature added.

GSM-WCDMA Inter-System Handover

Feature added.

GSM/EDGE 800/1900 Common BCCH

Feature added.

Dynamic Abis Allocation

Feature added.

GPRS

Figure of the GPRS network added.

Dual Band GSM 900 / 1800

Information updated and added on dual band 800/1900.

BSC3i

Information on the new BSC3i added.

Nokia High Capacity Base Station Controller, BSC2i

Table BSC configurations vs. capability updated.




Packet Control Unit (PCU) hardware in BSC

Information updated.

Dependency table

S10.5 dependencies added.

Capacity and performance

Rx antenna supervision by comparing RSSI value and TRX monitoring by RSSIremoved under section Operability.

Nokia Smart Radio Concept for EDGE (Nokia SRC)

Topic: 4 way uplink diversity and Interference Rejection Combining, IRC added.

Air synchronisation between BCFs

Title changed to: Clock synchronisation between Nokia UltraSite and Talk-familyBase Stations.

MS Location Services (LCS)

Title changed to Nokia mPosition" release 2 for E-OTD phones.

Nokia mCatch" rel1.0 Location Services for Legacy Phones

Information added.



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Summary of changes

1 Overview to GSM/EDGE FeatureDescription

GSM/EDGE Feature Description covers all existing features in the Nokia GSM/EDGE BSS system up to BSS10.5 ED level. The features are described briefly,but more information on the features is available in BSS documentation.

The new BSS O & M functions that are managed solely at Nokia NetAct havebeen omitted. Also the BSS O & M functions that are managed locally, but havebeen complemented recently to include additional Nokia NetAct management,have been omitted. These functions are described in Nokia NetAct" (OMC)product documentation.

Note that not all features work with all network elements. GSM/EDGE FeatureDescription includes the main hardware requirements and system compatibilityinformation for S10, S10.5 and S10.5 ED. For more detailed information, seeBSS documentation. For dependencies of previous releases, see Existing Featuresand Features under Development documents for the needed release.

Related topics


Coverage

Data � IP Multimedia

Operability

Transmission

Services

BSS10, BSS10.5 and BSS10.5 ED dependencies



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Overview to GSM/EDGE Feature Description

2 Capacity and performance

The features and functionalities presented in the following sections are related tothe capacity and performace of the Nokia BSS.

Back to Overview to GSM/EDGE Feature Description.

2.1 GSM-WCDMA Inter-System Handover

The GSM-WCDMA Inter-System Handover deals with handovers that occurbetween the GSM BSS and the WCDMA RAN. The handovers can take placefrom the GSM BSS to WCDMA RAN and vice versa when the mobile is in adedicated state. For a dual mode GSM/WCDMA mobile, the GSM-WCDMAInter-System Handover feature enables the measurements and cell re-selection ofa neighbour WCDMA network while the mobile is camped on a GSM cell in theidle state.

GSM-WCDMA Inter-System Handover is an optional feature in the BSC.

Benefits of GSM-WCDMA Inter-System Handover:

. When the networks overlap, handovers from GSM BSS to WCDMA RANcan be made in order to release traffic load in the GSM system.

. Handovers from WCDMA RAN to GSM BSS can be made in order for theoperator to provide a seamless coverage in areas where WCDMA is notavailable. The handover extends the radio network coverage.

. Due to the inter-system handover, seamless continuity of speechconnections and certain data services between WCDMA RAN and GSMBSS networks are available for all dual mode subscribers. Dual-modemobiles support both GSM and WCDMA systems.



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Figure 1. GSM-WCDMA RAN network architecture

Both the circuit switched and packet switched modes are supported.

Inter-system cell re-selection of the GPRS mobiles is supported in S10.5. NewSystem Information and Packet System Information messages and additions tothe existing ones are needed in order to enable the mobile to perform cell re-selection in the idle state. Handovers from/to the WCDMA RAN are alsosupported in S10.5. New messages and additions to the existing ones are neededto enable the mobile to send measurement reports to the network in the dedicatedstate.

For more information, see GSM-WCDMA Inter-System Handover .


GSM BSS Gb

Abis

Network Architecture

BTS

BTS

PSTN/ISDN

lub

WBTS

WBTS

WCDMA RAN

lu

WBTS

WBTS

A

RNC

lur

MSC/VLR GMSC

SGSN

3G-SGSN GGSN IPNETWORKS

HLR SCP

RNC

BSC

8.6.0-0

Dual mode




2.2 BCFA card with 4 Mb flash and DRAM

Due to the growing size of DF BTS-SW, the BCFA flash and DRAM memorysize has been increased to 4 MB. When BCFA card is used with DF4.0 or TRXboot, the SW is also stored in the flash memory of BCFA card. This removes theneed to load the TRX boot from the BSC after BTS reset, for example, when newBTS SW release has been background downloaded. The new BTS SW can beactivated without extra down time of the BTS caused by TRX boot SW loadingfrom BSC.

Note

This feature is applicable to Talk-family BTSs.


2.3 BTS time base reference from PCM

The master clock unit of the BTS can be adjusted according to the frequency ofthe incoming PCM signal. A 2 MHz signal is extracted from the PCM and isused as a reference when adjusting the output of the oven oscillator producing 13MHz for the BTS internal timing. This is not a phase-locked loop, but a longerterm averaging type of adjustment, the 13 MHz output is adjusted every 20minutes based on the 2 MHz. The requirement for the PCM is ± 0.015 PPM inorder to meet GSM requirement 0.05 PPM for clock accuracy on the Airinterface.

If the relation between the output of the master clock and the 2 MHz shows a bigdifference, an alarm is generated. There can be two reasons for this alarm, eitherthe incoming 2M signal is not correct, or the output of the master clock is notcorrect. The tuning, however, is continued, since the master clock cannot knowwhich one of the signals is incorrect.

When the tuning is completed and the relation between these two frequencies iscorrect, the alarm is cleared. The tuning can be controlled per site with thehardware database. If tuning is not used, then the master clock output is basedsolely on the oven oscillator. Also, if the 2 M PCM is disconnected, the tuning isstopped since the 2 MHz may not be accurate any more.



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When the PCM is reconnected, tuning is continued. The disconnection/reconnection is detected from the state of the O&M LAPD signalling link. If thelink is down, the 2 MHz is not used. Because the tuning period is so long, aspecial fast tuning method is available in 2nd generation BTSs for commissioningpurposes. With a command from BTS-MMI, the MCLP tunes itself according tothe incoming 2-Mb signal. The accuracy of this adjustment is not as good as forthe long-term adjustment, but it is sufficient for the commissioning.


2.4 BTS clock synchronisation

The Nokia PrimeSite offers one basic configuration, which can be flexiblyexpanded with BTS clock synchronisation. The PrimeSite has an extension clockinterface, which can be used to synchronise all PrimeSites on cell or site. Whenseveral PrimeSites are synchronised, one BTS functions as the clock source, themaster, and the other BTSs follow the master clock and act as its slaves.

The master BTS transmits frame clock and frame number signals to the extensionclock lines, while the other BTSs receive these signals to create internal clocksignals. The clock synchronisation is implemented by connecting the BTSs withextension clock cables. The BSC performs the clock synchronisation procedureand assigns the clock parameter values defined by the operator to PrimeSites.

The clock recovery is performed, if either the clock initialisation fails, or the BSCreceives a clock synchronisation alarm. The clock recovery always leads tominimum configuration; all PrimeSites except the BCCH PrimeSite of the cellare blocked by the BSC.

When setting the cell into the minimum configuration all the PrimeSites of thecell are configured to use their internal clock. The minimum configuration is notrecovered autonomously, but as a result of a user action. By default, the PrimeSiteuses internal clock for timing. The extension clock interface is designed formultipoint transmission on up to a 100m long chain. A longer distance betweenthe first and the last PrimeSite in the chain may cause synchronisation errors. Theextension clock lines have to be terminated at both ends of the chain by 120-ohmresistor adapters. For more information, see Operating System andSynchronisation.





2.5 DE34/DF34 four-way wideband combining with dualduplexing

AFE is a two-way wideband hybrid combiner with a diversity of four-wayreceiver multicouplers. It is possible to connect a number of AFEs into the samesector, thus enabling a combination of a number of transmitters into the antennas.If this combining technique is used together with Baseband Frequency Hopping,an additional benefit is that in average every other burst is transmitted via adifferent antenna, thus implementing downlink diversity.

An enhancement in the feature is '12 TRX Cell with Wideband Combining'support. This supports up to six combiner units per sector, which makes itpossible to utilise RF Hopping with up to 12 TRXs per sector. 12 TRX solutionuses six AFEs with six antennas, the antenna beams overlapping to cover thesame geographical area. Three cross-polarised antennas can be used to reduce thenumber of antennas to a minimum. Similarly, five AFEs (10 TRXs) requires fiveantennas, four AFEs (eight TRXs) requires four antennas or two cross-polarantennas, and three AFEs (six TRXs) requires three antennas.

The connection scheme per sector is as follows when using 4-TRX combiningwith dual duplexing. If duplexing is not used, four antennas per sector arerequired.

Both Nokia Intratalk and Citytalk cabinets support six AFEs, thus making itpossible to build a 3*4 TRX sectored site with wideband combining and with sixantennas.

The VSWR of the antenna carrying the BCCH is monitored during normaloperation. The other antenna does not have a continuous transmit signal, which ismandatory for the VSWR measurement. Therefore, the BCF must start acontinuous fixed level transmission on one of the TRXs connected to the otherantenna. For a reliable measurement, the transmission must be on for at least 500ms before measurement can be made. When measurement is completed,transmission is switched off. The transmission power used during the test is theBCCH power defined for this cell.

The above mentioned refers to the antenna supervision when Base Band Hoppingis not used. When it is used, it is necessary to activate transmission in all TRXsbelonging to the same hopping group in order to ensure continuous transmissionin antenna. Otherwise the procedure is the same.



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Ongoing calls are not disturbed. If there is a call ongoing in a TRX for which thecontinuous transmission is activated, it is maintained and no interruption tospeech to either direction occurs. For example, if the call is on timeslot 4, thetransmission on all other timeslots should also be activated. During themeasurement all timeslots, including timeslot 4, transmit on BCCH level. Aftermeasurement, transmit power of timeslot 4 is put back to the that set by the BSC.

The fact that all timeslots transmit on BCCH power means that MSs see anincrease in the received signal level during the test. The whole duration of theVSWR measurement is only one second. This is too short a time for the powercontrol algorithms to react.

The hardware configuration used must be entered into the hardware database withMMI.


2.6 Four-way wideband combiner

RF Hopping can be used with up to eight TRXs in the same cell with only twoantennas. Fot that, a four-way hybrid combiner filter unit with eight Rx outputs isneeded. These combiners are used in pairs to support eight TRXs with diversityreceive.

No special BTS or BSC software support is made, so the O&M detects four AFEsinstead of the two AFCs.


2.7 Downlink diversity

PrimeSite has downlink diversity function, which offers improvements in airinterface link performance. The PrimeSite has two RF transmitters, one connectedto each antenna. In the downlink diversity technique, the transmission ofsuccessive frames is altered between the antennas. The MS receives a signal firstfrom one antenna and then from the other. If the MS is in a fade on the radio pathfrom one antenna, it most likely still receives a good signal from the otherantenna.

The downlink diversity can be configured on or off by PrimeSite hardwaredatabase. Downlink diversity is available on the PrimeSite basic configuration.There are always two transmitter amplifiers available. Downlink diversity servesas redundancy for power amplification function.





2.8 FOC algorithm for 2nd generation BTS

An MS does not have an accurate frequency reference. Instead, it uses the signalreceived from BTS to derive necessary information to adjust its clock. When anMS is moving, it continues to adjust its own clock according to received signal,which is distorted by the Doppler shift. The MS uses this signal as a referencewhen it generates transmission towards BTS, that is, the frequency oftransmission is already shifted by Doppler.

Because of the movement of the MS, the BTS sees a signal that has twice theDoppler shift for a given speed. In practice this means that the BTS receiver hasto cope with double Doppler shifts while the MS receiver can compensate fullyfor the Doppler shift it detects. The ETSI specifications do not take Doppler-doubling effect into account.

The performance requirements for both uplink and downlink are equal in thisrespect despite that a BTS needs to cope with worse conditions. Frequency OffsetCorrection (FOC) algorithm can correct most of the above phenomena, providingthat the Doppler shift is either positive or negative.

The frequency offset (FO) is calculated for each burst and averaged over oneSACCH multiframe. This averaged FO is used in the FOC to correct the bursts ofthe subsequent SACCH-multiframe. During the correction new average iscalculated. In the Line-of-Sight case, correction is relatively easy since signal isDoppler shifted to only one direction. The above described FOC algorithm isbased on TalkFamily and PrimeSite solution originally implemented in DF2.0and further improved in DF4.0.


2.9 Redundant cold stand-by TRX

The BTS may contain a redundant TRX , which can be brought into traffic in caseof a BCCH TRX failure in a 1 TRX BTS. In the sectored case, a separate stand-by TRX is required for each sector. This stand-by TRX uses the same Abistransmission resource as the failing unit. Thus, there is no need to reserve anyextra capacity for the redundant TRX.

When the BTS OMU detects that the primary BCCH TRX of the BTS has failed,it sends alarms to the BSC. Then the following steps are taken:



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. The BIE is reconfigured to divert the traffic of the failing TRX to theredundant TRX.

. The combiners are re-tuned, and the CU is given the appropriate channelnumber.

. The OMU switches on the redundant TRX, loads and initialises it.

Now the alarms raised for the failing unit are cancelled, and the BSC brings thenew TRX into use. This changeover is transparent to the BSC, since it onlyreceives alarms for the failing TRX and then the cancellation of the alarms. Itdoes not know that it is now communicating with a different hardware.


2.10 Redundant/ floating TRX

This feature provides two ways to secure the BCCH-TRX operation in a sectoredBTS. A redundant TRX can be taken to traffic in case of a BCCH-TRX failure ina sectored 1+1+1 BTS. Thus, a redundant TRX replaces a broken BCCH-TRX.

The FTS (Floating Transceiver Switch) is used to switch the redundant TRX fromone sector to another. This redundant TRX uses the same Abis transmissionresource as the failing unit, thus there is no need to reserve any extra capacity forthe redundant TRX.

A floating TRX can also be configured as a TCH TRX. In case of a BCCH-TRXfailure, this floating TRX replaces the BCCH-TRX of any sector. A floating TRXcan be switched to any sector by means of FTS. A typical configuration would be2+1+1, where the second TRX of the first sector is a floating TRX. After a failureof any BCCH-TRX, the site becomes a 1+1+1 site. The FTS reserves the place ofone TRX unit thus reducing the maximum capacity. FTS cannot be installed intoNokia Flexitalk. The support for floating TRX exists only in the Nokia Talk-family BTS.

Note

There is a feature called Cold Standby Redundant TRX for Nokia 2ndgeneration. Its functionality is the same as the one described in the first choice forfloating TRX, except that the TRX cannot be switched between sectors.Therefore each sector for which this redundancy is required needs to be equippedwith its own redundant TRX.





2.11 Six sector support

Features like ICE (Intelligent Coverage Enhancement ) call for support to morethan 3 sectors. This support is now developed into the software in order to allowthe BTS to be divided from 1 to 6 sectors. The combiner type (AFH, AFT, AFE,and RTC) can be freely selected to each sector independently of other sectorsfrom the software point of view.

However, only three RTCs may be defined. Some combinations may not bepossible because of cabling and space limitations. Also, the number of antennaconnectors limits the possible configurations. The main principle of this feature isto remove possible SW limitations in such a way that the only thing limitingpossible configurations are those set by cabling, physical space and the number ofantenna connectors.


2.12 Nokia MetroSite Base Station configurations

The Nokia MetroSite BTS is a modular BTS for 1 - 4 TRXs. The BTS consists ofthe following units:

. up to 4 TRXs

. interface unit

. transmission unit

. power supply unit (AC230V, AC110V or DC)

. cooling fan unit

Logical BTS configurations

There is no limitation for sector configurations in the Nokia MetroSite BTS,because each transceiver has its own antenna connector. The only limitationscome from using of diversity; more than one transceiver per sector is needed fordiversity.

Dual Band BTS

The Nokia MetroSite BTS can be used as a GSM 900/1800 Dual Band BTS.

Combined BCF and TRX functions



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The transceiver can be configured as a master or slave. Master transceiver handlesO&M and Telecom functions.


2.13 External interfaces of Nokia MetroSite Base Station

Air

Each TRX has an antenna connector for external antennas. Nominal RXsensitivity is -108dBm. Nominal maximum TX output power at antennaconnector is 5W. Diversity is provided when more than one transceiver isinstalled per sector.

Abis

The transmission unit takes care of the transmission between the Nokia MetroSiteBTS and the BSC through the Abis interface. The transmission media can beeither radio link or wire line (E1/T1). The transmission unit interconnects theNokia MetroSite BTS and the BSC using point-to-point, star or loop networkconfigurations. The Nokia MetroSite BTS supports 16 kbit/s, 32 kbit/s and 64kbit/s Abis TRX signaling. Similarly the O&M signaling speed can be 16 kbit/s,32 kbit/s or 64 kbit/s. The Nokia MetroSite BTS also supports combined O&Mand Telecom signalling. Locally, the transmission configuration is managed withthe Nokia MetroSite Manager.

The following radio link transmission unit is available for the Nokia MetroSiteBTS:

. FXC RRI: 16 x 2 Mbit/s, support for 2 microwave radio outdoor units,grooming, branching and loop protection support, cross connection on 8kbit/s level.

FC RRI and (OUT) FXC RRI transmission units are compatible with the NokiaMetroHopper Radio and the Nokia FlexiHopper Microwave Radio.

The following wire line transmission units are available for the Nokia MetroSiteBTS:




. FC E1/T1: 1 x 2 Mbit/s (E1) or 1 x 1.5 Mbit/s (T1) PCM connection, (onecoaxial 75 ohm TX and RX interface connector for E1 use, one twistedpair 100/120 ohm TX/RX interface connector for either E1 or T1 use).

. FXC E1/T1: 4 x 2 Mbit/s (E1) or 4 x 1.5 Mbit/s (T1) PCM connections,(either four coaxial 75 ohm TX and RX interface connectors for E1 use, orfour twisted pair 120/100 ohm TX/RX interface connectors for either E1 orT1 use), grooming, branching and loop protection support, cross-connection down to 8 kbit/s level

The FC E1/T1 operates as the termination point in a star or chain topologynetwork. The FXC E1/T1 transmission unit interconnects the Nokia MetroSiteBTS and the BSC using point-to-point, chain, star or loop networkconfigurations.If more transmission capacity is needed, Nokia MetroHubTransmission Node can be used with Nokia MetroSite BTS.Local ManagementPort for BTS and transmission units

The LMP connector provides the physical RS-232 connection.

Q1 for transmission units

Common Q1 connector is located at interface and clock unit, and provides thecontrol interface for co-sited transmission equipment.

External Alarm and Control (EAC)

The number of EAC inputs is 10 and number of outputs is 4.

External D-bus

External D-bus interface is provided for BTS extensions.

Power Supply

Power supply alternatives are:

. 230 VAC

. 110 VAC

. DC power supply for 36 VDC/48 VDC/60 VDC voltages

The power supply is capable of feeding power to the maximum BTSconfiguration including two Nokia MetroHopper Radio outdoor units or twoNokia FlexiHopper Microwave Radio outdoor units.

Grounding point



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The grounding cable can be connected to chassis.

User interface and visual operation indicators

The single 3-colour LED is used as an operation indicator for the following units:

. transceiver

. power supply unit

. cooling fan unit

. interface unit

. transmission unit


2.14 Nokia UltraSite GSM/EDGE Base Stationconfigurations

The Nokia UltraSite GSM/EDGE BTS is a modular BTS with the maximumconfigurations of:

. 1-12 TRX/sector

. 1-6 sectors/cabinet

. 1-12 TRX/cabinet

Nokia UltraSite GSM/EDGE Base Stations can be chained together for largerconfigurations. The maximum number of Nokia UltraSite GSM/EDGE BTSs in achain is 9. In case of chaining Nokia Talk-family BTSs with Nokia UltraSiteGSM/ EDGE BTSs the maximum number of cabinets is 6.

Configurations cover all possibilities from 1 Talk-family BTS + 5 UltraSite GSM/EDGE BTSs to 5 Talk-family BTSs + 1 UltraSite GSM/EDGE BTS. Whenseveral Nokia UltraSite GSM/EDGE BTSs are synchronised, the master BTSfunctions as the frame clock source to the slave BTSs. If Nokia Talk-family BTSis chained with the Nokia UltraSite GSM/EDGE BTS, the master BTS is alwaysthe Nokia Talk-family BTS.

Nokia UltraSite GSM BTS Indoor and Outdoor are BTSs for up to 12 TRXs andNokia UltraSite GSM BTS Midi Indoor is a cabinet for 6 TRXs. All threecabinets consist of the following common units:




. Base Operations and Interfaces unit (BOI)

. Up to 6 dual baseband units (BB2)

. Up to 12 transceiver RF-units (up to 6 in Midi Indoor)

. Integrated battery back-up, optional in Indoor and Outdoor cabinets

. Up to 4 transmission units

. Up to three DC or up to two AC power supply units

Additionally they have the following units:

Indoor and Outdoor cabinets Midi Indoor cabinet

Cabinet cooling fan unit, only in Outdoor cabinet

Cabinet heating unit, optional in Outdoor cabinet

Combining units, optional

Multicouplers

Dual Duplex units

Dual Band Duplex units

Unit cooling fans

Booster unit(s), optional

Combining units, optional

Multicouplers

Dual Duplex units

Dual Band Duplex units

Unit cooling fans

Booster unit(s), optional

Figure 2. Nokia UltraSite GSM/EDGE Base Station Indoor



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Figure 3. Nokia UltraSite GSM/EDGE Base Station Outdoor

2.15 External interfaces of Nokia UltraSite GSM/EDGEBase Station

Antenna interface

The total amount of antenna connectors is 12. Six of them are optional.

Abis interface

The Transmission unit takes care of connecting Nokia UltraSite GSM/EDGEBTSs with each other and to the rest of the network through the Abis interface.The transmission media can be either radio link, wire line (E1/T1). NokiaUltraSite GSM/EDGE BTS supports 16 kbit/s, 32 kbit/s, and 64 kbit/s Abis TRXRF signaling. The O&M signalling speed can be 16 kbit/s or 64 kbit/s.

Radio Transmission

The following radio link transmission unit is available for the Nokia UltraSiteGSM/EDGE BTS:

. FXC RRI: 16 x 2 Mbit/s, support for two Flexbus interfaces, grooming,branching, and loop protection support, cross-connection on 8 kbit/s level.




FXC RRI transmission units are connected to the Nokia FlexiHopperMicrowave Radio or Nokia MetroHopper Radio with a coaxial Flexbuscable. Moreover, when multiple cabinets are located at the same site, it ispossible to connect BTS cabinets together by using the Flexbus cables,provided by FXC RRI units.

The FXC RRI operates as a repeater and interconnects Nokia UltraSiteGSM/EDGE BTS and the BSC using point-to-point, chain, star or loopnetwork configurations.

Optical Fiber Transmission

Optical Fiber Transmission is provided by third party devices.

Wire Line Transmission

The following wire line transmission units are available for the Nokia UltraSiteGSM/EDGE BTS:

. FXC E1: 4 x 2 Mbit/s (E1) PCM connections, four coaxial 75-ohm TX andfour coaxial 75-ohm RX connectors for E1 use, grooming, branching, andloop protection support, cross-connection down to 8 kbit/s level.

. FXC E1/T1: 4 x 2 Mbit/s (E1) or 4 x 1.5 Mbit/s (T1) PCM connections,four twisted pair 120-/100-ohm TX/RX connectors for either E1 or T1 use,grooming, branching, and loop protection support, cross-connection downto 8 kbit/s level. Interfaces can be configured independently either E1 orT1 mode.

. FC E1/T1: 1 x 2 Mbit/s (E1) or 1 x 1.5 Mbit/s (T1) PCM connection, onecoaxial 75-ohm TX and one coaxial 75-ohm RX connector for E1 use, onetwisted pair 120-/100-ohm TX/RX connector for either E1 or T1 use.

The FXC E1 and FXC E1/T1 transmission units interconnect the NokiaUltraSite EDGE BTS and the BSC using point-to-point, chain, star, or loopnetwork configurations. The FC E1/T1 operates as the termination point ina star or chain topology network.

Power supply interface

Power supply alternatives are -48VDC and 230 VAC input voltage.

ILMT interface



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This is the interface between the Nokia SiteWizard PC and Base Operations andInterfaces (BOI) unit. The ILMT interface is physically a Local Management Port(LMP) connector located in the BOI unit and it is a multi-point communicationlink conforming to NOKIA Q1. The ILMT interface also supports managingtransmission units.

Q1 interface for transmission units

This provides control line to co-sited transmission equipment. Inside the NokiaUltraSite Support is space for customer equipment e.g. LTE. There is one Q1common to the installed equipment.

Q1 interface for Site Support System

This provides a control line to the Nokia UltraSite Support and the NokiaUltraSite EDGE BTS integrated battery backup.

Alarm and control interface

This is used for external controls and for collecting external alarms for BaseOperations and Interfaces (BOI) unit. There are 24 alarm lines and 6 control lines.

External clock interface

This is used for clock synchronisation between Nokia UltraSite EDGE BTScabinets. This interface consists of frame number and frame clock signals.


2.16 Nokia InSite Base Station configurations

The Nokia InSite Base Station can be used as a stand alone single transceiverBTS. It has two HDSL (1 Mbps) type Abis interfaces and an E1 interface. SeveralNokia InSite Base Stations can be chained together using two wire telephonecables. The maximum length between Nokia InSite Base Stations is 2.0kilometres. A Multidrop feature can be used.

The Nokia InSite Base Station can also be connected to the Nokia FlexiHopper orthe Nokia MetroHopper microwave radios via a FIU 19 indoor unit.

The unit has a compact construction covered by separate covers that can bereplaced easily. The construction is designed to maximise heat conductivity andminimise size.




Due to its small size and low weight, the Nokia InSite Base Station is very easy tohandle during installation and assembly.

Figure 4. Nokia InSite Base Station


2.17 External interfaces of the Nokia InSite Base Station

Antenna interface

The Nokia InSite Base Station has its own built-in antenna, but external antennascan also be used.

Abis

Two ETSI HDSL (High bit-rate Digital Subscriber Line) interfaces including aclock distribution are used for the Abis connection. The HDSL interfaces providea 1Mbps signal on a single-pair wire.

The E1 interface can also be used for Abis connection. It conforms to thespecifications for an ETSI E1 terminal equipment interface.

With a Nokia InHub Data Service Unit in use, a T1 connection can also be used.

Local Management Port for BTS and transmission units

This is the physical and logical interface between the BCF part of the basebandmodule of the transceiver unit and a Local Management Tool (LMT). The LocalManagement Port (LMP) is located in the baseband part and is a multi-pointcommunications link conforming to the Nokia Q1E specification. The LMP alsoprovides debugging interfaces.



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User interface and visual operation indicators

Visual indicators show the status of the Nokia InSite Base Station:

Description Colour On Blinking Implementation

Power Green Power supply on Low supply voltagelevel

Supply voltage ADCreading with fixedthreshold

Call On Green At least one call on BCCH testtransmission ON

TS allocationcounter

Device Error Red BTS initialisation inprogress

BTS internal error Any self test failed(blinking), BTS bootgoing on (LED isswitched off whenCONF_COMPLETEmessage is sent toBSC)

Transmission Error Red Abis Linkinitialisation

No Abis link Transmission status-LED lit untilOMUSIG LAPD linkis properlyestablished

Power Supply

The Nokia InSite Base Station has a connector to supply the DC power.


2.18 BSC clock and tone generator

The Clock and Tone Generator (CL1TG) plug-in unit generates the basic timingsignals needed in the BSC, either independently or synchronised to a framealignment signal provided by the Exchange Terminal (ET). In a single-rack BSC,the CL1TG distributes the basic timing signals directly to the cartridges needingthem, while a BSC composed of two racks contains a special Clock and AlarmBuffer (CLAB) for the distribution of basic timing signals. In addition to the basictiming signals, the CL1TG also generates the tones needed in the BSC. TheCL1TG also supervises the operation of the clock equipment and tone generatorand conveys supervision data to the Operation and Maintenance Unit (OMU).The active CL1TG synchronises the operation of the back-up unit.




CL3TG can be optionally equipped to a BSC. The CL3TG has improved EMCproperties when compared to CL1TG. Frequency stability in the CL3TG is as inthe CL1TG. In the printed board, signal wirings are covered between the earthlayers. The edges of basic timing signals going out from the unit are made lesssteep. Filtering in the incoming direction of the power supply is improved. TheESD tolerance of the outgoing basic timing circuits is improved.

Usage/equipping: The user can connect up to four synchronisation inputs to theunit. Also, two external synchronisation sources can be connected to the unit. Therequirement for the CL3TG is that the CLOC cartridge is equipped to the BSC.This means that in some older BSCs, the CLAC cartridges need to be replacedwith CLOC cartridges before the CL3TGs can be installed. CL3TG must not beinstalled to work together with the CL1TG, except temporarily, when the plug-inunit is changed.

Note

CL3TG is optional for the BSC. The following table clarifies the differencesbetween the versions of the CLxTG:

Synch inputsfrom ETs

ExternalSynchInputs(G.703)

Oscillatorstability/day

CL1TG 3 � 5E-9

CL3TG 4 2 5E-9

For more information, see CL1TG and CL3TG, CL3TG-S, CL2TG-S.


2.19 Call release after loss of TRAU framesynchronisation

If the TRAU loses its frame synchronisation between the BTS and the transcoderfor over one second BTS sends a connection failure message with cause remotetranscoder failure to the BSC. The BSC releases the call. The reason for the lossof synchronisation can be for example a failure in transmission. A switch over toa possible redundant transmission path (for example loop protection) can take



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longer than one second. To maintain the call, a new parameter is implementedinto the BSC to indicate after how many remote transcoder failures the call isreleased. BTS repeats the remote transcoder failure in one second periods untilBSC releases the call or the frame synchronisation is obtained again.


2.20 Ciphering

Ciphering is one of the security procedures defined to protect subscriber identityand data. When Ciphering is active, all information exchanged between the MSand the network on the dedicated radio channels is encrypted. The key previouslyset between the network and the MS is used to encipher and to decipher theencrypted information.

During the authentication procedure, in which the identity provided by the MS ischecked to prevent unauthorised use, the ciphering key Kc is set between thenetwork and the MS. The ciphering key must be stored in the BSC for assigning anew channel, because the same key is used for one transaction. The featureenables the usage of different A5 algorithms (currently A5/1 and A5/2) and givesan alternative of using no ciphering at all (A5/0). A5/2 allows ciphering to beused in some market areas, as in some areas the use of A5/1 is forbidden. Theuser cannot set the ciphering mode, because the MSC has the possibility toindicate to BSS all ciphering algorithms. A selection of the ciphering algorithm tobe used is based on a BSS level system parameter, which determines the allowedalgorithms and their fixed preference. The preference, which currently is A5/1first, then A5/2 and A5/0 as the last, cannot be changed by the operator. For BTSthree different software packages are available: A5/1,2,0 packet, A5/2,0 packetand A5/0 packet. In the BSC ciphering method must specified in the softwarepackage in the customer specific data.

The following assumptions are made:

. One ciphering algorithm in the network at a time is supported, that is,multiple ciphering is not supported.

. An A5/1 phase 1 network does not check the spare bits. See ETR 09.90 .

. A phase 1 MS is not disturbed upon receiving an unknown RR message.




Table 1.

MS Ciphering used Network Case

A5/1 A5/1 A5/1 1.

A5/1 no ciphering no ciphering 2a.

A5/1 connection released no ciphering 2b.

A5/1,A5/2 A5/1 A5/1 3.

A5/2 A5/2 A5/2 4.

Case 1: Call is established normally according to phase 1.

Case 2a: If no ciphering is available in the network the call is established withoutciphering. The decision of this is made by the MSC and the ciphering procedureis initiated towards the BSC.

Case 2b: The network (MSC) tries to use A5/1 ciphering even when the BSS(BSC or BTS) does not support encryption (if disabled). In this case, the endresult is that the call is released.

Case 3: The network ignores the A5/2 capability of the MS and continues the callestablishment including ciphering with A5/1 which should also be supported bythe MS.

Case 4: Call is established normally including ciphering with A5/2.

For more information, see Basic Call .


2.21 Discontinuous reception (DRX)

The BSC calculates the correct paging group for a paging message according tothe IMSI of the subscriber who is being paged. This group number is added tothe paging message sent to the BTS. The BTS schedules this paging message fortransmission over the Air interface in the correct paging group as commanded bythe BSC. This feature enables MSs to listen to only their own paging group and



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thus prolongs battery lifetime considerably. Only one CCCH timeslot issupported. The BTS supports all paging request types 1, 2 and 3. This allowsefficient use of downlink CCCH as several mobiles can be paged by onemessage.


2.22 Mode modify procedure

Mode modify procedure includes the configuration of transmission devices on theinfrastructure side (BTS,TRAU and BSC ) and the configuration of the MS. Thepurpose of this feature is to modify the channel type within the used TCH. Thepossible changes are:

. signalling to speech

. speech to data

. data to speech

. data transmission speed

The ASSIGNMENT REQUEST message from the MSC starts theprocedure.


2.23 Nokia High Capacity Base Station Controller, BSC3i

Nokia High Capacity Base Station Controller BSC3i is a new solution for theevolving GSM markets. The maximum circuit handling capacity of the BSC3i is660 TRX, 3920 Erl. BSC3i is compact with only one cabinet and is modulardesign in order to enable easy expansion. It has built-in IP connectivity forenhanced feature support with IP based interfaces. It uses transmission and radioresources efficiently in order to enable a flexible traffic mix between voice anddata. It has a swift fault detection and hot standby units to allow minimal systemdowntime.

S10.5 software supports BSC3i. It includes the same features as BSC, BSC2i andBSC2E/A products. BSC3i uses a generic SW platform with all BSCs and has acommon SW build and environment definition package with S10.5 release.




BSC3i radio network configuration

Maximum radio network configuration in BSC3i:

. 660 TRXs (110 TRX per BCSU)

. 248 BCFs (43 BCFs per BCSU)

. 248 BTSs (248 BTSs per BCSU)

. 10560 SDCCHs (1760SDCCHs per BCSU)

. 5280 TCHs (880 TCHs per BCSU)

. 660 CCCHs (110 CCCHs per BCSU)

The maximum number of LAPD links per BCSU is 163-170. Improved combiAS7 functionality is needed to meet the requirement of LAPD links.

BSC3i hardware configuration

. the same functional unit types as in current BSC products

. Max 2 PCUs per BCSU

. The same platform is in use for all GSM/EDGE DX200 network elements(for example, MSCi, HLRi and 2G SGSN )

BSC3i is a new BSC variant. Current BSCs cannot upgraded to BSC3i. Wide SS7signalling (256 kbit/s) links support new network element type for BSC3i.

For more information, see BSC3i .



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Figure 5. BSC3i


2.24 Nokia Large Capacity Base Station Controller,BSC2E/A

BSC maximum capacity is increased to 256 TRX, 248 BTS, and 200 BCF, butthe sum of Full Rate and Half Rate TCHs may not exceed 2048. This amount ofcapacity can be upgraded to both old, high BSCs and BSC2s just by replacing/adding boards. This capacity increase step is based on the utilisation of the 486/100MHz CPUs.

The replacements needed for the old BSC are:

1. group switch GSWB with two SW64B plug-in units

2. 486/100MHz CPUs in all units (OMU, MCMU, BCSU)




Additional boards needed for the old BSC are AS7-Us per BCSU to handlethe increasing amount of LAPD links.

The changes with BSC2s are similar with the exception that new AS7-Us are notneeded.

The maximum number of ET2E/As in BSC2E/As is 40, enabling 80 externalPCMs (extra ET2E/A cassette is required for upgrading PCM capacity from 64 to80 in BSC2E/BSC2A).

The following table clarifies the differences between the 'normal' and 'large' BSCconfigurations:

Configuration 128 TRX BSC 256 TRX BSC

Supported in BSC Types BSCE, BSC2E, BSC2A BSCE, BSC2E, BSC2A

Maximum Radio networkconfiguration

128 BCF, 128 BTS, 128 TRX 200 BCF, 248 BTS, 256 TRX

Allowed CPU Type (in all units:OMU, MCMU, BCSU)

CP4C32, CP4HL/HX CP4HL/HX (Intel486/ 100MHzCPU)

Allowed Group Switch type/Maximum number of PCMs

GSW/256, GSWB/128 GSWB/128

Maximum Number of externalPCMs

56 /BSCE 56 /BSC2 56 /BSCE, 80 /BSC2

Large BSC's maximum call handling capacity is doubled compared to normalBSC meaning 46 000 BHCA and 1520 Erl with the reference call mix.

For more information, see Base Station Controller BSC2E/A, BSCE.


2.25 Nokia High Capacity Base Station Controller, BSC2i

The High Capacity BSC is a feature in the DX200 Base Station Controller, whichenhances the growth of network capacity. The feature enables an even moreefficient BSC usage and also full use of the existing BSCs.



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The High Capacity BSC feature enables using a maximum of 512 TRXs and 248BTS/BCFs in upgraded BSCE or BSC2E/A, that is, 31 BCFs per BCSU and 248BTSs per BSC. The prerequisite is that the BSC fulfills the hardwarerequirements, that is, the BSC should be configured as an i-model (BSCi orBSC2i).

The BSCs can also be upgraded to fulfill the hardware requirements of thisfeature. The BSCs should have the S6 Large Capacity BSC optional featureimplemented in order to be able to use this feature. This upgrade to HighCapacity does not require full configuration of BSC, that is, 8 working BCSUs.

The traffic handling capacity of the High Capacity BSC increases to 3040Erlangs and 91000 BHCAs (Busy Hour Call Attempts) with the reference callmix described in High Capacity Base Station Controller BSC2i, BSCi.

Figure 6. BSC2i

BSCE upgrade to BSCi

The configuration can be upgraded into already installed BSCEs.

By making the required HW changes, and with the High Capacity BSC optionalfeature, the operator can increase the maximum number of TRXs, BTSs, andBCFs. The increase does not require the maximum number of BCSUs (eight) tobe working. It can be done with one to eight BCSUs if other requirements arefulfilled, all BCSUs must have the plug-in-units of same HW type.

It is possible to add two extra ET5C cartridges to BSCE when upgrading toBSCi, High Capacity BSC. The ET5C cartridge contains eight ET2Es, all ofwhich provide two PCM interfaces. To implement the extra ET5Cs, the new massmemory cartridge SD3C-S must also be installed. This optional HW enables theBSCi to provide maximum of 88 external PCM lines.

Mandatory hardware:




. CPU type: CP6LX, which includes a minimum amount of 64MBytesRAM. CP6LX is based on a Pentium II processor.

. A GSWB with two SW64B plug-in units, if not already installed.

. AS7-U(s) in every BCSU are replaced with three AS7-Vs, that is, threeAS7-Vs and one AFS-T plug-in-unit in every BCSU.

. Q1 and LapD terminal in the OMU changed to an AS7-V plug-in unit.

. SERO-T taken into use for the LPT and VDU (replaces the SCSIF).

. Connector panel for additional VDU, LPT interfaces.

. LAN connection is provided by CP6LX, no COCEN card needed.

. Minimum NetAct link speed 64 kbit/s.

Optional hardware:

. Two ET5C cartridges if the maximum number of external PCMs isincreased from 56 to 88.

. Mass memory cartridge SD3C-S.

. One additional SW64B plug-in unit in both SW1C cartridges (=192PCMs). A front panel connector SWBUS3 is also needed.

BSC2E/A upgrade to BSC2i

By making the required HW changes and with High Capacity BSC optionalfeature, the operator can increase the maximum amount of TRXs, BTSs, andBCFs. The increase does not require the maximum number of BSCUs, which iseight,to be working. It can be done with one to eight BCSUs if other requirementsare fulfilled, meaning that all BCSUs must have the same HW type.

This generation of equipment allows the number of PCMs to be increased to amaximum of 112. Currently the maximum number is 80 with the 256 TRXfeature.

Mandatory hardware:

. CPU type: CP6LX, which includes a minimum amount of 64MBytesRAM. CP6LX is based on a Pentium II processor.

. A GSWB with two SW64B plug-in-units, if not already installed.

. MBIF-UA plug-in-units installed in the MCMU, OMU, and BCSUs.

. AS7-U(s) in every BCSU are replaced with three AS7-Vs, that is, threeAS7-V plug-in-units in every BCSU.



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. Q1 and LapD terminal in the OMU changed to an AS7-V plug-in unit.

. SERO-T taken into use for the LPT and VDU (replaces the SCSIF).

. Connector panel for additional VDU and LPT interfaces.

. LAN connection is provided by CP6LX, no COCEN card needed.

. Minimum NetAct link speed 64 kbit/s.

Optional hardware:

. Two ET5C cartridges if the maximum number of external PCMs isincreased from 80 to 112.

. An additional SW64B plug-in unit in both SW1C cartridges (=192 PCMs).(Needed, if optional ET5C cartridges are installed). A front panelconnector SWBUS3 is also needed.

BSC deliveries

A number of different configurations are likely to exist in operators' networks. Toassist in establishing the BSC configurations that can be supported, the tablebelow shows the BSC configurations vs. capability.

Configuration A

BSCE andBSC2E/A, nolarge options

B

S6 LargeCapacityBSCE andBSC2E/A

C

S8 HighCapacityBSCi

D

S8 HighCapacityBSC2i

BSC3i

Supported in BSCTypes

BSCE,BSC2E/A

BSCE,BSC2E/A

BSCE BSC2E/A BSC3i

Maximum Radionetwork configuration

128 BCFs,128 BTSs,128 TRXs



248BCFs,248BTSs, 512TRXs


Maximum number ofPrimeSites

128 256 256 256 256

Allowed CPU type in theOMU and MCMU /Minimum size ofmemory in megabytes

CP4HX/128,CP4HL/128,CP6LX/128,CP6MX/128


CP6LX/128,CP6MX/128

CP6LX/128,CP6MX/128

CP710/256

Allowed CPU type in theBCSU/Minimum size ofmemory in megabytes



CP6LX/64,CP6MX/128

CP6LX/64,CP6MX/128

CP710/256




Allowed Group Switchtype/Maximum numberof PCMs

GSWB/128 GSWB/128 GSWP/128/GSWB/192

GSWB/128/GSWP/192/GSWP/256

GSWP/256

Number of AS7-U cardsin BCSUs

2 - 3 3 - 0-1 �

Number of AS7-V cardsin BCSUs

- - 3 2�3 �

Maximum number ofexternal PCMs

56 /BSCE 80 /112 /BSC2

56 /BSCE 80 /112 BSC2

56/88 80/112/144 124

Type of LapD and Q1terminal in the OMU

AS7-U AS7-U AS7-V AS7-V AS7�B

Minimum number ofWO-EX BCSUs

1-8 8 1-8 1-8 1�6

Number of BCFSIGLapD links per BCSU

16 32 32 32 43

Number of TRXSIGLapD links per BCSU

16 32 64 64 110

Maximum number ofLapD links per BCSU(BCFSIG+TRXSIG+ISDN+ET-LapD)

64 64 117 124 163�170

Maximum number ofTCPCMs per BCSU

11 12 23 23 39

Maximum number ofSDCCHs per BCSU

384 384 768 768 1760

Maximum number ofTCHs per BCSU

256 256 512 512 880

Note

The weakest CPU determines the maximum radio network configuration, that is,if there is at least one CP4C32 CPU in the BSC, the BSC supports configurationA. If there is at least one CP4HX and no CP4C32 CPUs in the BSC, the BSCsupports configuration B. If all CPUs are of the CP6LX type, the BSC cansupport configuration C (BSCi) or D (BSC2i).



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Note

Configurations B, C, and D can only be supported if the S6 Large Capacity BSCfeature is activated. This does not apply to the BSC2i deliveries.

Note

The maximum number of PrimeSites depends also on the LapD capacity of thecurrent configuration. Due to that, it is not possible in all configurations to createmaximum amount of PrimeSites.

Note

There is an AS7-V card In ETSI that is used for SS7 signalling purposes inBCSU, in ANSI there is AS7-US card for that purpose.

. NetAct Large BSC Management & NetAct High BSC Management

. Two ET5C cartridges and SW64B plug-in unit in both SW1C cartridges ifthe maximum number of external PCMs is increased from 80 to 112. Afront panel connector SWBUS3 is also needed. The BSCi requires SD3C-Sand two ET5Cs to get 88 external PCM lines.

. ANSI HW is different from ETSI

. supported by NPS/X

For more information, see High Capacity Base Station Controller BSC2i, BSCi.





2.26 Dynamic SDCCH allocation

The feature Dynamic SDCCH makes it possible to configure the SDCCHresources according to the actual SDCCH traffic situation of a cell. When a BTStemporarily needs larger SDCCH capacity than normally, the idle TCH resourcesare configured for the SDCCH use by the BSC. When the SDCCH congestionsituation is over the extra SDCCH resources are configured back to TCHresources.

Special benefit is derived from the feature in the traffic cases where the signallingis the only transmission mode during the connection to the network. ShortMessage Service (SMS) traffic as well as location updates are counted amongthem. In some special places - airports, ports - the location updates can producesudden short time SDCCH traffic peaks which can be handled without any needto configure extra permanent SDCCH capacity for peak usage times only.

The operator is required to configure to the BTS the minimum static SDCCHcapacity sufficient to handle the normal SDCCH traffic.

Extra SDCCH resource is allocated only when the actual SDCCH congestionsituation has fallen after the last free SDCCH is allocated. Consequently, whenthe dynamic SDCCH radio resource is completely free again it is immediatelyconfigured back for TCH use. Thus, the maximum number of TCHs is always intraffic use, depending on the actual need of the SDCCH resources at eachmoment.

For more information, see Dynamic SDCCH in Radio Channel Allocation.


2.27 Half Rate

Half Rate is a feature designed to maximise the spectrum efficiency by doublingthe amount of radio resources as compared the use of the Full Rate trafficresources only.

Each radio timeslot of the BTS TRX can be configured to be a Full Rate (FR),Half Rate (HR) or Dual Rate TCH resource. In the latter case, the BSC is able toallocate an idle radio timeslot either for Half Rate or Full Rate codingdynamically on a call basis.



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Full Rate speech and data are coded and transferred by using 16 kbit/s channels inthe BSS. With the half rate coding, an 8 kbit/s transmission can be used on theAbis interface. The A- interface supports different types of transcoders capableof Full Rate coding or Half Rate coding, or both.

It is possible to introduce the Half Rate coding to existing Full Rate GSMnetwork gradually. The BSS is able to co-operate with both old Full Rate MSsand with MSs which support both Full and Half Rate.

Traffic channel allocation

In cases when the MSC does not determine the channel type uniquely, the BSCalways first decides on the channel rate of the TCH to be allocated. Though the Ainterface circuit allocated by the MSC must enable the BSC to allocate a radiochannel of requested type, the actual A interface circuit pool configurationdetermines how the BSC can select the channel rate. In those cases when the Ainterface circuit, which the MSC has allocated, belongs to a pool which does notsupport the type of TCH BSC to be allocated, the BSC can request the MSC toswitch the circuit to the appropriate pool.

The Radio Resource Management of the BSC is able to optimise the allocation ofthe Half Rate traffic channel resources of the cell in such a way that they areprimarily allocated from such radio timeslots where there is already maintained aHalf Rate call.

There are two main factors which are determining the type of TCH, or rather, thespeech (codec) version in the traffic channel allocation done by BSC: the trafficload of the cell and in handover case also the speech version which the call isusing in the source cell of the handover.

Traffic channel allocation based on the traffic load of BTS

Type of traffic channel - Half Rate or Full Rate - to be allocated can bedetermined according to the actual traffic load of a cell. Full Rate TCHs areallocated from the BTS until the number of free full rate resources are reducedbelow a particular lower limit, the Half Rate resources are then allocated. Whenthe number of the free Full Rate resources of the cell increases above a particularupper limit, Full Rate TCHs are allocated again.

For more information, see Half Rate in BSC .

Back to Overview to GSM/EDGE Feature Description .




2.28 GSM/EDGE Dual Band

The Dual Band GSM 900/1800, 800/1900 and 800/1800 Network Operationfeatures provide the means to manage traffic between GSM 900 and GSM 1800,GSM 800 and GSM 1900 and between GSM 800 and GSM 1800 frequencybands.

Here is a list of general information on the Dual Band GSM 900/1800, GSM 800/1900 and GSM 800/1800 Network Operation.

. One BSC is able to handle GSM 900 and GSM 1800, GSM 800 and GSM1900, or GSM 800 and 1800 cells, which can be set as neighbour cells.

. A handover is possible between the cells of a different bands.

. The frequency hopping between bands is not supported .(see referenceETR 366.1997.)

. The BSC supports the extension of the GSM 900 frequencies. Theextended GSM 900 (EGSM 900) functionality is implemented as a genericfeature. In other words, a handover between PGSM 900 and EGSM 900frequency bands is a generic feature. Optional dual band refers to thehandovers between GSM 900 and GSM 1800, GSM 800 and GSM 1900,and GSM 800 and GSM 1800 frequency bands.

Extended GSM 900 frequencies are supported as separate cells in the BSC.

The Dual Band GSM 900/1800, GSM 800/1900 and GSM 800/1800 NetworkOperation are optional features in the BSC. The support of EGSM 900 band is ageneric functionality.

For more information, see Dual Band Network Operation .

Tri-band

This feature supports the use of the ETSI-specified GSM900 frequency bandextension. According to the ETSI GSM 05.01 specification, in some countries itmay be possible to allocate an extra frequency band for the GSM900 from thearea of 880-890 MHz uplink and 925-935 MHz downlink (10 MHz below thecurrently used 25 MHz sub-bands).

In case the whole extension band could be utilised, the number of frequenciesavailable would increase from 124 to 174. The E-GSM900 (extended GSM900)band consists of the absolute radio frequency channel numbers 975 to 1023. Thechannel number 0 (zero) is also taken into account. This means that a total of 50radio frequency channels are included in this E-GSM900 band.



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For a GSM operator, the E-GSM900 extension band can represent the most cost-effective way of adding capacity to the system if the Primary GSM spectrum isused.

The BSS8 Tri-Band release provides an implementation in which the E-GSM900and P-GSM900 frequencies are configured in separate cells. In other words, thefrequencies from the primary GSM900 band and the frequencies from theextended GSM900 band cannot be configured in the same cell. This featurerequires also support from the MS.


2.29 Intelligent Underlay-Overlay (IUO)

Intelligent Underlay-Overlay is a feature designed to allow the operator to reusefrequencies more intensively and hence achieve a higher radio network capacity.

In order to avoid interference due to the increased level of frequency reuse, theBSC estimates the degree of interference on different frequencies and directs theMSs to those frequencies that are "clean" enough to sustain a good radioconnection quality.

The interference estimation made by the BSC is based on the downlinkmeasurement results reported by the MS via the BTS and on various adjustableparameters.

In order to achieve a higher radio network capacity by means of the IntelligentUnderlay-Overlay feature, the operating spectrum of the network is divided intoregular frequencies and super-reuse frequencies. Continuous coverage area isprovided by the overlay network utilising regular frequencies. Frequencyplanning of the overlay network is based on conventional planning criteria usingsafe handover margins and requiring low co-channel and adjacent channelinterference probabilities. Regular frequencies are intended to serve MSs mainlyat cell boundary areas and other locations where the C/I ratio is the worst. Theoverlay network also provides interference-free service in the overlapping cellareas required for handover control and neighbouring cell measurements by MSs.The underlay network is formed from the super-reuse frequencies, which arereused very intensively to provide the extended capacity. The super-reusefrequencies are intended to serve MSs, which are close to the BTS, insidebuildings and other locations where the radio conditions are less vulnerable tointerference.

The BSC controls the traffic division on regular and super-reuse frequencies bymeans of radio resource allocation at the call setup phase and later on during thecall by means of handover procedures.




The direct access to super-reuse TRXs that give extra capacity is determined bysignal level measurements during call setup and in handovers. The access is onlyaccepted if the signal level is above a given threshold (Rx level). The directaccess to super-reuse TRX also helps in situations where the MS is near to theBTS. In this case the unnecessary TCH reservation from the regular TRX isavoided.

The BSC continuously monitors the downlink C/I ratio on each super-reusefrequency of the cell for every ongoing call. The call is always handed over froma regular frequency to a super-reuse frequency when the C/I ratio on the super-reuse frequency is sufficient. If the C/I ratio on a super-reuse frequency becomesworse, the call is handed over from the super-reuse frequency back to a regularfrequency. Based on the profile of interference each MS is exposed to, the BSCdetermines the most appropriate frequency to be assigned for the call connection.A handover between frequency groups as a direct handover from a super-reusefrequency group to another super-reuse frequency group was introduced in BSS7.

The BSC uses different handover decision algorithms for handovers caused bytraffic control between regular and super-reuse frequencies, handovers caused byconventional radio criteria such as power budget, and handovers caused by otherreasons than radio criteria such as directed retry.

The signal strength may vary and drop rapidly in cases, where the MS moves fastthrough the coverage area of one cell. This drop can happen also in street cornercases. When the IUO is used and the call in handled by the super-reuse TRX, inthese rapid field drop cases both bad C/I and power budget thresholds can triggerat the same time. This can happen especially when the call is in the edge of thedominance area of the super-reuse TRX. In this case it is preferred to do ahandover to an adjacent cell due to power budget instead of handing the call overto regular TRX and to perform the power budget handover to an adjacent cellafter the IUO handover from super-reuse TRX to regular TRX.

The Handover and Power Control algorithm is modified for the simultaneous useof Intelligent Underlay-Overlay and Dual Band. The behaviour of the dual bandmobiles in IUO network is indicated with one parameter. This parameter indicateswhether dual band mobiles are allowed to use super reuse TCHs in a dual bandcell. This parameter is BSC specific parameter.

The Intelligent Underlay-Overlay feature does not have any special requirementsfor the RF power control strategy. The service area of super-reuse frequencies iscontrolled by the C/I calculation method together with quality report analysis, notby limiting the maximum allowed MS/BTS TX power levels. The algorithmsallow MSs to use high power levels in difficult conditions, such as insidebuildings.



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Frequency hopping can be applied in an Intelligent Underlay-Overlay cell. It canbe defined on the IUO layer basis in order to further increase the interferenceperformance. By combining the benefits of Intelligent Underlay-Overlay andFrequency Hopping it is possible to have a powerful radio spectrum efficiencyfeature available.

Improvements:

. inter super-reused layer handover

. additional reference cells

. direct access to super-reuse TRX in IUO

. handover cause prioritisation in IUO

. dual band MS access to IUO layer

For more information, see Intelligent Underlay-Overlay .


2.30 Frequency Hopping (FH)

Frequency Hopping is a feature designed to increase the quality and capacity inthe urban propagation environment. The gain is achieved by means of frequencydiversity and interference diversity properties of Frequency Hopping.

Slow Frequency Hopping in GSM 900/1800 means that the frequency of radiotimeslot (RTSL) is changing burst by burst. The frequency remains the sameduring a burst (0,577 ms). All dedicated channel types and their associatedchannel types (TCH /SACCH /FACCH , SDCCH/SACCH) may hop. The exactfrequency on a certain moment of time is defined as a function of frequencyhopping parameters of a cell and a 'logical Air interface channel' (CA , MA,MAIO , HSN) and the absolute frame number in Air interface. The frame numbersynchronises MS and BTS operation on a time basis.

As far as the implementation of frequency hopping is concerned there are twomain options; Baseband Hopping and Radio Frequency (RF) Hopping. NokiaBSS supports both of these hopping methods. However, RF hopping is notsupported by the Nokia 2nd generation BTS.

Whether frequency hopping is in use or not is defined on a cell basis.

If frequency hopping is applied in an Intelligent Underlay-Overlay cell (option), itcan be defined on IUO layer basis.




Baseband Hopping

When Baseband Hopping is in use in a cell, all the timeslots, except the BCCHtimeslot, hop. The number of frequencies in a hopping sequence is the same asthe number of TRXs in the hopping group.

Radio Frequency Hopping

When RF hopping is in use in a cell only the timeslots on other TRXs than theBCCH TRX hop. The frequencies in the hopping sequence are defined byattaching the cell to one of the Mobile Allocation Frequency Lists. The operatormay define up to 128 different frequency lists per BSC, each list containing up to63 frequencies (possible only if BTS SW is DF3.0).

Shared frequencies in sectored site

It is possible to use the same MA frequency list in sectors of a BTS site providedthat the following conditions are met:

. the sectors are synchronised, that is, they are controlled by the same BCF

. applicable for RF hopping only

. the MA-list contains at least as many frequencies as there are hoppingTRXs in the site

. the sectors are configured to use the same HSN (hopping sequencenumber)

Frequency sharing makes it possible to utilise RF hopping in cells having arelatively small number of TRXs, still without any need to allocate morefrequencies for the BTS site.

For example, with a BTS of three sectors, and two TRXs in each sector, at leastthree frequencies to hop over in each sector plus BCCH frequency are needed.Without frequency sharing this totals 12 frequencies for only 6 TRXs, which isquite an uneconomical use of frequency band.

By sharing the same MA frequency list between the three sectors it is possible tomanage with only 6 frequencies: 3 for BCCH TRXs and 3 for hopping TRXs.The hopping TRX in each of the three sectors hops over the same 3 frequencies,but synchronised in a way that no collisions occur.

For more information, see Frequency Hopping.




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2.31 Intelligent Frequency Hopping (IFH)

This feature allows the use of Frequency Hopping separately for both layers of anIUO cell. By combining the benefits of Intelligent Underlay-Overlay andFrequency Hopping, a powerful radio spectrum efficiency feature is available.Additionally, the quality benefits of Frequency Hopping in avoiding frequencydependent fading in radio path.

For gradual roll-out, it is possible to make only one or the other of the IUO layershopping. Both baseband hopping and RF hopping methods are supported, thoughonly one method within a BCF.

For more information, see Intelligent Underlay-Overlay and FrequencyHopping.


2.32 Double Mobile Allocation (MA) list amount

Heuristic planning improves capacity and the quality of frequency allocation.Due to that the number of MA lists is increased (comparing to easy planning (1/1or 1/3)). Intelligent Frequency Hopping (IFH) with double number of hoppinggroups and High Capacity BSC (512 TRXs/248 BTSs) together with heuristicplanning increases the number of MA lists further.

By doubling the number of MA lists from 128 to 255, both the frequencyplanning and implementation of new frequency plan become easier.

Heuristic planning of IFH, leads to a slightly higher capacity than can be obtainedvia the easy IFH approach. Operators that do not want to use the heuristicapproach have to customise the MA list for each cell in order to take theinterference and hopping conditions into consideration on a cell by cell basis. It isthus important to be able to offer a sufficient large number of MA lists so thatheuristic planning is possible.


2.33 Flexible MAIO management

With this feature it is possible to arrange MAIO s within a cell in a way that usingsuccessive frequency channels becomes possible without continuous in-celladjacent channel interference.




This functionality is of vital importance for success of RF hopping with tightreuse, because commonly the operators are forced to allocate successive channelsin MA lists.

To utilise RF Hopping flexibly, the operator needs the management access to allthe hopping parameters, including MAIOs. Thus, the possibility to define theMAIOs to be used in the cell is needed. A simple way to offer such manageabilityis to provide:

. user defined parameter to set the starting point for allocation of the MAIOsper cell, the lowest in a cell can be bigger than zero (This is implementedalready in S6.)

. user defined parameter to allow discontinuous MAIO numbering to beused in a cell, for example, MAIOs 0,2,4,6


2.34 C/I Based Handover Candidate Evaluation

C/I Based Handover Candidate Evaluation is a feature designed to direct MSs tocells which can provide interference-free service at the current location of eachMS, and in that way improve the quality of service.

The C/I estimation is based on the radio measurements. The feature is tuned byvarious adjustable parameters related to the correlated behaviour of the radionetwork.

The BSC calculates the potential C/I ratio for handover candidate cell at thecurrent location of the MS by comparing the transmitted downlink signal level ofthe handover candidate cell (carrier) and the measured downlink signal level ofthose adjacent cells which may have high correlation to co-channel or adjacentchannel interference. The interfering cells can be defined independently for eachhandover candidate (adjacent) cell.

The BSC ranks the handover candidate cells, which meet the required radio linkproperties according to priority levels. The potential co-channel or adjacentchannel interference in a handover candidate cell affects the order of preferenceof the target cells through the priority level of the cell:



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. small or non-existent interference in the cell keeps the priority of thehandover candidate cell unchanged, or if required increases the priority ofthe handover candidate cell

. bad interference in the cell reduces the priority of the handover candidatecell or if required the BSC removes the cell from the list of preferredhandover candidates


2.35 Radio Channel Allocation

Radio Channel Allocation is used in the BSC to search and allocate available freeradio environment resources (SDCCHs, TCHs). The BSC allocates radioresources so that it takes interference, the load of the cell and rotation of resourcesinto account.

The network operator can define the minimum C/N ratio cell by cell basis. Thisratio is used by the channel allocation algorithm in order to allocate the mostsuitable time slot. The following example illustrates how this works:

CNThreshold = 20 dB Uplink signal level = -78 dBm

Interference band 0 -110 ... -105 dBm

Interference band 1 -104 ... -100 dBm

Interference band 2 - 99 ... - 95 dBm



Maximum interference level = -78 dBm - 20 dB = -98 dBm

The BSC allocates a radio channel with an interference band of 1 if available. Ifnot, the BSC can allocate a channel with an interference band of 0, 2, 3 or 4.

The network operator can define with a BTS level parameter that the trafficchannels in the cell are allocated primarily from the BCCH TRX, or that TCHsare allocated primarily outside the BCCH TRX of the BTS.

The actual channel search depends, in addition to the requirements included in theresource request, also on the available resources in the BTS. The four mainprinciples are followed in the single slot TCH allocation procedures:




. Efficiency of the search procedure: a quick pre-selection of a resource canbe performed by maintaining the general information concerning thenumber of available resources and their distribution between the TRXs of aspecific BTS.

. Rotation of allocatable resources: successive allocations of certain type ofchannels are directed to separate TRXs inside the BTS, to separate TSLsinside the TRX and to separate subchannels inside the TSL.

. Availability of different channel rates: channels in permanent rate TSLsare allocated primarily so that allocation of a channel of one rate type doesnot restrict the availability of the resources of the other channel rate type.Dual rate resources for HR traffic are allocated primarily from a halfoccupied DR TSL so that as many dual rate timeslots as possible can bemaintained available also for FR traffic.

. Avoiding collision between HSCSD and speech calls: when the overalltraffic load in the BTS is high, TCHs for single slot allocations are selectedfrom the ends of a TRX thus saving gaps of successive idle TSLs forpossible HSCSD calls.

In multislot allocation for HSCSD, call requests multiple TCH/Fs in a TRX canbe allocated. HSCSD call configurations of up to four TCH/Fs are possible.


2.36 GSM handover and power control algorithms

Handover strategy

Handover and Power Control Algorithm is a feature designed to make themobility of the MSs possible during a call and to maintain good speech/dataquality. Furthermore, the battery lifetime of an MS can be optimised. A versatilehandover and power control algorithm enables the efficient use of air interfaceresources.

The handover decisions made by the BSC are based on the measurement resultsreported by the MS/BTS and various parameters set for each cell. The standardhandover algorithm is capable to start handover due to following reasons:

. decreased signal level of serving cell

. decreased signal quality of serving cell

. umbrella criteria

. power budget criteria



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. O&M reason

. distance reason (Timing Advance)

. traffic reason (see Traffic Reason Handover Procedure in BSC. )

The crucial principle for the BSC selecting the target cells for the handovercaused by radio criteria (signal level / signal quality) is that the adjacent cell mustbe better than the current serving cell in order for the handover to be useful. If thehandover is caused by reasons other than radio criteria, it is not necessary for thetarget cell to be better than the serving cell. It is enough that the target cell servesthe call sufficiently; for example, a handover from an umbrella cell to a microcellis performed whenever the call can be maintained on the neighbouring microcell.

The BSC supports handovers, which occur between different channels of TRX,between different TRXs of BTS, between different BTSs of BSS and betweendifferent BSSs of NSS(s). The handover can occur between signalling channels(SDCCH to SDCCH) or between traffic channels (TCH to TCH). In case ofDirected Retry the handover can occur from signalling channel to traffic channel(SDCCH to TCH).

The handover can be synchronised or asynchronised, depending upon whetherthe cells are synchronised or not.

RF power control strategy

The RF power control strategy employed by the BSC defines the RF powercommand that is signalled to the MS, and the RF power level that is used by theBTS. The RF power control optimises the RF output power of the MS and theBTS and simultaneously ensures that the signal level required at the BTS/MS issufficient to maintain adequate speech/data quality.

The RF power level to be employed in each case is based on the measurementresults reported by the MS/BTS and on the various parameters set for each cell.All parameters controlling the power control procedure are administered on acell-by-cell basis.

The power control, for both the BTS and the MS, runs independently in parallelwith the handover, but in such a way that the power control detects the status ofthe handover and vice versa, that is, the BSC does not try to adjust the MS/BTSpower level in the current serving cell and execute a handover to a neighbouringcell simultaneously.

The RF Power Control and Handover Algorithm controls the intervals betweenhandovers and handover attempts by means of timers:




. minimum interval between handovers related to the same connection

. minimum interval between an unsuccessful handover attempt and thefollowing handover attempt

The Bad Quality Experience Guard Time improvement concerns the control ofthe intervals between handovers and handover attempts.

For more information, see RF Power Control and Handover Algorithm .


2.37 Traffic Reason Handover

Traffic Reason Handover is a feature designed to share the load between the cellsand so improve the trunking efficiency.

The BSC informs the MSC of the amount of working and idle resources (perinterference band) per cell. The MSC may request the BSC to perform a specifiednumber of handovers from one specified cell (high load) to other specifiedadjacent cells (less load). The BSC examines which calls, if any, can be handedover from the serving cell to some of these specified adjacent cells. The targetcells for traffic reason handover are ranked according to downlink signal level ofadjacent cells. So Traffic Reason Handover is possible also to weaker cells thanserving one.

For more information, see Traffic Reason Handover Procedure in BSC.


2.38 Directed Retry (DR)

Directed Retry is a feature designed to improve the trunking efficiency in case oftemporary congestion.

In case of call setup (mobile originated or mobile terminated) when congestionoccurs in serving cell the MS can be handed over to the traffic channel of anadjacent cell. The adjacent cell selection is based on downlink signal level. If thatexceeds the operator-defined threshold (as per adjacent cell basis) the DirectedRetry can be performed.



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RxLevMin RX Level

Cell B -100 dBm -92 dBm

Cell C -100 dBm -105 dBm

Cell D -100 dBm -85 dBm

The operator can also define a separate, adjacent cell specific threshold for thesignal level. This threshold value is used when deciding if the adjacent cell isselected as a candidate cell in the Directed Retry procedure or not.

In case the MS is camped in cell A, but congestion occurs, the MS measures alsocells B, C and D. The downlink signal levels of cells B and D exceeds theoperator defined thresholds and so directed retry is possible to cells B and D butnot to cell C. The MS attempts to hand over to cell D because its downlink signallevel is higher that of cell B. If congestion occurs also in cell D then the MS istried to hand over to cell B.

A cell specific parameter defines the minimum time after which DR handover toanother cell is started. During this delay a call set up is queuing for a TCH in thecongested cell if queuing feature is in use. Due to this delay, more measurementsare available for the DR candidate cell list evaluation.


2.39 FACCH call set-up due to SDCCH congestion

The feature improves the quality of service in the network in case of SDCCHcongestion. In FACCH call set-up, the MS is assigned from a CCCH to a TCH -instead of a SDCCH - with the IMMEDIATE ASSIGNMENT procedure. TheTCH is used for signalling, and thus no assignment procedure is needed in the Airinterface. Instead, only the MODE MODIFY procedure to the TCH channel isrequired to change the channel mode from signalling to speech.

SDCCHs are primarily used when an MS requests a dedicated channel from theBSS. Traffic channels can be allocated to mobiles in immediate assignment, if allSDCCHs are already reserved for signalling, such as call set-ups, SMSs andsupplementary services. For each BSC, the FACCH call set-up can be set on oroff by means of the MMI.

For more information, see FACCH Call Set-up .





2.40 Discontinuous transmission downlink and uplink(DTX)

This description includes features Tone Detection in FR VAD and TrainingSequence Change.

Discontinuous transmission (DTX) is a mechanism allowing the radio transmitterto be switched off during speech pauses. This feature reduces the powerconsumption of the transmitter, which is important for MSs, and decreases theoverall interference level on the radio channels affecting the capacity of thenetwork.

The BSS supports both downlink and uplink discontinuous transmission.

The discontinuous transmission is implemented in Transcoder Submultiplexer(TCSM) by means of three main structural elements. On the transmitting side aVoice Activity Detection (VAD) is required for detecting whether the signal inquestion contains speech or just background noise. The silence is not transmitted,but the information about the background noise level is. The VAD function ismainly based on analysing the energy of the signal and spectral changes. Inaddition, a function for counting the parameters of the background noise isrequired on the transmitting side.

On the receiving side comfort noise is generated on the basis of noise parametersreceived from the transmitting side in order to avoid disturbing variations ofcomplete silence and speech with background noise for the listener on thereceiving side. Background noise is generated synthetically towards the trunk inthe transcoder and for the MS in the MS itself.

There is a system parameter in the BSC, which determines the value of thedownlink DTX flag, if the MSC does not prevent the activation of the DTXfunction. The default value of this parameter is "Downlink DTX disabled". Fordata calls the value of the downlink DTX flag is always disabled regardless of theparameter value.

The mode of uplink DTX is defined in the BTS parameters in BSC database.



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When the downlink DTX is being used together with Frequency Hopping, someMSs have difficulties in separating good downlink speech frames from poor ones,if BCCH frequency is included in the mobile allocation list. This can be avoidedif the training sequence of the dummy burst being transmitted is altered while thedownlink DTX is active. This makes it easier for the MS to reject bad speechframes with the DTX.

ETSI has specified several alternative methods as the correction of this problem.Nokia has implemented the option number 2.

For more information, see TCSM2 Functionalities .


2.41 Advanced Multilayer Handling (AMH)

The Nokia Advanced Multilayer Handling (AMH) is used to redistribute traffic tothe appropriate layer or frequency band according to the prevailing load of thenetwork. Therefore, AMH can smooth out the traffic over the network. Thisprocedure is also supported on an inter-BSC basis.

The AMH concept consists of three different features, which are related tonetwork load:

. BSC initiated Traffic Reason Handover

. IUO load control

. Multilayer load control

The AMH concept is feasible especially in multiband, microcellular or multilayer(Nokia Intelligent Underlay-Overlay) networks by providing the operator bothimproved quality and capacity.

AMH provides the network operator with the tools to relieve the load of thecongested cells and smooth out the load over the network. It provides operatorswith the tools to use only overlay network during low traffic periods and thusavoid additional handovers between two layers. Therefore, it is extremelyefficient in multilayer networks.

AMH can also be applied efficiently with Nokia Intelligent Underlay-Overlay toavoid congestion in overlay layer and thus provides more trunking gain. AMH isable to redistribute the traffic from congested regular layer to other cells, selectingthe best MS and cell combination that is likely to give good quality on the newcell.




AMH also includes tools to avoid additional handovers (Ping-Pong) back toheavy loaded cell by introducing particular penalty system. Therefore, the MSscannot be directed back to the original heavy-loaded cell before the penalty timeris expired.

In general, by using Nokia AMH and setting AMH related parameters, operatorscan move the capacity between different layers according to prevailing traffic.

For more information, see BSS8123:Advanced Multilayer Handling andAdvanced Multilayer Handling with IUO in Intelligent Underlay-Overlay.

BSC initiated TRHO (Congestion relief)

The AMH concept provides the network operator with the tools to relief load ofthe congested cells and smooth out the load over the network. The overall trafficload of the network can be smoothed out by using BSC initiated TRHO feature.The basic idea of the feature is to dynamically change the power budget marginsand thus direct theMSs hanging around in the cell border to less loaded adjacentcells.

BSC initiated TRHO is based on radio frequency resource indications of idlechannel interference (load information) which are sent from the base transceiverstation (BTS) to the base station controller (BSC). If the traffic load of theserving cell exceeds a parameter AmhUpperLoadThreshold (set for eachBSC by means of the O & M), AmhTrhoMarginPBGT (set for each BTS bymeans of the O & M) is used for all same layer adjacent cells in the power budgetequation instead of the existing HoMarginPBGT . The basic evaluationalgorithm calculated according to radio link properties is based on the followingstrategy and order:

1. AV_RXLEV_NCELL(n) > TRHO_TARGET_LEVEL(n) + Max(0,(MS_TXPWR_MAX_CELL(n) - P))

2. .PBGT (n) > AmhTrhoMarginPBGT and PBGT (n) < HOMarginPBGT

If the PBGT value is between AmhTrhoMarginPBGT and HOMarginPBGT ,the handover is triggered due to TRHO handover. If the PBGT value exceeds theHOMarginPBGT, the handover is triggered due to PBGT handover.

Furthermore, the TRHO candidate have to have less thanAmhMaxLoadOfTgtCell (set for each BSC by means of the O & M) reservedtraffic channels in order to become target cell. The BSC maintains the status ofavailable channels and according to prevailing traffic, it can allow the TRHOchannel allocation.

Note



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Queuing is not used with a BSC initiated TRHO.

Sometimes the traffic has to be directed to weaker cells. Therefore, a specialmechanism for handling that kind of traffic, keeping the call in the new cell, isalso added to the concept. The parameter TrhoGuardTime (set for each BSCby means of the O&M) determines the penalty time to handover back to originalcell because of PBGT handover and therefore consecutive handovers back tooriginal cell during the guard time is prevented.

Note

Parameter TrhoGuardTime is also be used with MSC controlled handover.

Note

Only calls from regular layer can be redirected due to traffic reason handover.

IUO load control

IUO is applied into the network to increase capacity. In periods where thecapacity needs are not so high, the IUO functionality still performs manyhandovers. Therefore, by avoiding the additional handovers between differentfrequency layers, the quality of the network can be improved.

AMH can be used to prevent the use of IUO during very low traffic and thus keepthe MSs only in the overlay network. The solution is based on the traffic load ofserving cell.

If the traffic load of the serving cell go under AmhLowerLoadThreshold , theIUO handover, Direct Access to Super-reuse TRX and IUODR are not allowed.The functionality is controlled by parameter AmhTrafficControlIUO (setfor each BSC by means of the O & M).




Dual band/micro cellular network load control

Many operators build capacity by using micro cells or a Dual Band solution. Theincreasing amount of different network layers also increase the number ofhandover between layers. During very low traffic, for example, during nights, theneed for extra capacity is unnecessary and therefore underlay capacity is notneeded. Therefore, the adequate capacity can be achieved by using only overlaynetwork.

On the other hand, during night time, most of the traffic is generated fromoutdoor environment, particularly from fast moving vehicles. Furthermore, fastmoving MSs in the microcell network generates many handovers with relativehigh speed. Therefore, it is more reasonable to keep the traffic in the overlaynetwork instead of underlay to provide better quality to end-users.

AMH can be used to prevent the use of microcell/DCS (GSM 1800 / GSM 1900)layer during very low traffic, and thus keep the mobiles only in the macrocell/GSM (GSM 800 / GSM 900) network, once they have camped on it.

If the traffic load of the serving cell goes under AmhLowerLoadThreshold ,the FMMS, MS Speed Detection and Umbrella handovers are not allowed tolower layer cells. The functionality is controlled by parameterAmhTrafficControlMCN (set for each BSC by means of the O&M).

Note

The access to microcells cannot be prevented, but C2 reselection can be used tokeep the fast moving mobiles in the overlay network during idle mode.

Interaction with other features:

AMH multilayer load control has lower priority than the Direct Access to DesiredLayer/Band (DADL/B) feature.

Direct Access to Desired Layer/Band

HSCSD

The BSC initiated TRHO is only made for single-slot connections. The parameterUpperLimitCellLoadHSCSD should be set to a greater value than theparameter AmhUpperLoadThreshold . Thus unnecessary downgrades areavoided and radio resources are used efficiently.



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2.42 Dynamic Hotspot

Dynamic Hotspot is a feature designed to control traffic in a frequency hoppingradio network on the basis of interference and hence to achieve higher radionetwork capacity.

Dynamic Hotspot enables the usage of very tight frequency reuse of hoppingTRXs without quality degradation since the BSC can limit traffic intensity inareas where interference tends to increase above an acceptable level. Anotheradvantage is that with unequal traffic distribution, some cells can dynamicallyhandle more traffic than others can when traffic intensity in the other cells isrelatively lower.

The BSC monitors the level of interference by means of the measurement resultsreported by the MS/BTS. The degree of soft blocking is fully controlled by meansof adjustable parameters.

When the Dynamic Hotspot feature is employed by the BSC, the radio resourcemanagement limits traffic intensity in areas where interference tends to increaseabove an acceptable level. The radio resource management limits traffic intensityby dynamically rejecting TCH requests in situations of excessive interferencealthough there might be free TCHs available (soft blocking).

Soft blocking concerns traffic channel allocation from RF hopping TRXs in acall, in an inter-cell handover, and in an underlay-overlay handover. It is notapplied in an intra-cell handover within a frequency group. Traffic channels onBCCH TRXs are available at all times; that is, soft blocking does not concernthese channels. However, in base band frequency hopping the BCCH TRX istreated as non-BCCH TRXs.

The soft blocking algorithm is based on the following criteria:

. traffic intensity in a cell

. radio connection quality in the interfered cells

The BSC begins to apply the soft blocking algorithm when the number of busyTCHs in a BTS exceeds a predetermined threshold limit. This threshold limit iscontrolled on a cell-by-cell basis. If the number of busy TCHs in the BTS is lowerthan the threshold limit, radio resource management may always allocate a TCHaccording to the requirements included in the resource requests.




When the number of busy TCHs in the BTS exceeds the threshold limit, radioresource management verifies the signal quality (percentage of bad uplink/downlink quality) in those cells (interfered cells) that use the same hoppingfrequencies (one or more) as the BTS and are sufficiently close to be interfered.On the basis of this verification, radio resource management calculates aprobability, which is used to determine whether a TCH can be allocated or not.

When signal quality is good in every interfered cell, the probability is 1. Thus,radio resource management may allocate a TCH from the BTS.

If signal quality is below an acceptable level in a single interfered cell, radioresource management may not allocate a TCH, that is, the probability is 0.

If signal quality is at least acceptable (=between good and poor) in everyinterfered cell (but not good in all cells), an adjacent-cell-specific probability ofchannel allocation is determined for each adjacent cell by comparing the adjacentcell signal quality to the signal quality threshold table. The threshold table isdefined by the operator (see the example below). The final probability is achievedby multiplying all adjacent-cell-specific probabilities.

The probability is then compared with a fixed reference value (50). The TCHrequest is accepted if the probability is greater than the reference value.

Example: A super-reuse TCH is requested from an RF hopping BTS. The numberof busy super-reuse TSLs exceeds the thresholdSoftblockingThresholdOnSuperReuseFrequency , thus the softblocking algorithm is activated. The BTS has two interfered cells, A and B,which use the same hopping frequencies. The signal quality in cell A is belowBadQualLimit , but above SigQualLimit1 . The signal quality in cell B isbelow SigQualLimit2 , but above GoodQualLimit . The operator hasdefined the probabilities of TCH allocation according to the table below:

Signal Quality % Probability %

>= BadQualLimit0<BadQualLimit >= SigQualLimit1

51 (TCH Probability1)

< SigQualLimit1 >= SigQualLimit2 72 (TCH Probability2)

< SigQualLimit2 >= GooQualLimit 80 (TCH Probability3)

< GoodQualLimit 100



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The probability of allocating a TCH in this example is 40% (0.51*0.80 = 0.40).GoodQualLimit , BadQualLimit , SigQualLimit andTCHPropability are adjustable parameters.

For more information, see Dynamic Hotspot .


2.43 Direct Access to Desired Layer/Band

The purpose of the feature is to reduce the number of unnecessary TCHreservations in macro cells, and thus to provide more trunking efficiency in thenetwork.

The Direct Access to Desired Layer/Band (DADL/B) feature directs traffic in callsetup phase from the SDCCH of a macrocell / GSM 900 / GSM 800 cell to theTCH of a microcell / GSM 1800 / GSM 1900 cell whenever possible. In addition,the extended GSM 900 band capability of the MS is taken into account. Thefunctionality of this feature is similar to that of Directed Retry . The difference isthat handover in DADL/B is triggered due to cell load and the target cell selectioncriteria are tighter.

The DADL/B handover can also be made in an other direction, from a micro cellto a macro cell or from a GSM 1800 / GSM 1900 cell to a GSM 900 / GSM 800cell. The use of DADL/B is flexible with adjacent cell specific indications and itcan be tailored to different environments and concepts.

Note

DADL/B feature is applicable to phase 1 mobiles, which do not support C2 cellre-selection.

DADL/B is applied if DADL/B is enabled in the BSC and if the load of theaccessed cell is higher than the BTSLoadThreshold defined for the accessedcell and there are adjacent cells defined as DADL/B handover target cells with thedadlbTargetCell(n) parameter. The adjacent cells are verified accordingto the MS capabilities (single band, dual band, and tri band).




If there is real TCH congestion in the accessed cell, a DR due to congestion withor without queuing is made. If there are TCHs available in the accessed cell, theBSC acts according to the DADL/B usage determination and cell load. If DADL/B is applied and TCH load in the accessed cell is higher thanBTSLoadThreshold , the DADL/B handover procedure is started. If DADL/Bis not applied or TCH load is lower than BTSLoadThreshold , a TCH isallocated from the accessed cell.

Note

Pre-emption always has higher priority, the TCH is allocated from the accessedcell, and thus no DADL/B handover is attempted.

The target cells for DADL/B handover are selected according to the followingcriteria:

Adjacent cells handled by the BSC handling the accessed cell, considered asDADL/B target cells with signal level exceeding HOLevelUmbrella , is sortedaccording to adjacent cell priority and load factor (HOPriorityLevel orHOPriorityLevel(n) - LoadFactor(n) if adjacent cell is loaded) to beused as target cells for DADL/B handover.

The DADL/B handover attempt can fail due to following reasons:

. a TCH cannot be allocated from any cell included in the DADL/B list(TCH congestion in DADL/B target cells)

. the DADL/B handover fails and the MS returns to the old channel(SDCCH)

. the timer monitoring the DADL/B target cell list availability triggers. Thistimer is the same as the timer used in Directed Retry (MinTimeLimitDR).

In these cases, an attempt is made to allocate the TCH from the accessed cell. DRand queuing are possible in the second TCH request if no TCHs are available inthe accessed cell. The BSC evaluates the target cells for DR as soon as possible.This means when at least one target cell for DR is found.

Note

The DADL/B handovers are only possible as intra-BSC handovers.



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2.44 Nokia Talk-family Base Station synchronisation

This feature provides timeslot and frame number synchronisation for differentNokia Talk-family BTSs located at the same site. The feature is implemented byinstalling BCF cards. The BCF card is a unit in the BTS, which is responsible forO&M functions of the BTS and timing of the transceiver units (TRXs). The BCFcard can be set to be master or slave by a switch, and it includes input and outputfor clock signals. When several base stations are synchronised, one BTS is set towork as master and the remaining ones are set to work as slaves. The mastersynchronises its internal clock to the incoming PCM transmission line and deliverclock signals and frame number via clock cable to the slave BTSs.

When BTSs are synchronised, hopping sequences run in a fixed relationship andsynchronised handovers between different BTSs are possible.

This initial solution is hardware only and needs no software support from theBSC or BTS. Synchronisation is supported for Nokia IntraTalk and CityTalkBTSs.


2.45 Nokia PrimeSite single branch combining

Nokia PrimeSite has two separate transmit/receive branches: main and diversity.In case of main branch failure, PrimeSite automatically switches the transmissionover to the diversity branch. With this feature, the diversity branch can bedisabled completely to prevent the switchover from taking place if the mainbranch becomes faulty. This is needed in PrimeSite configurations where only themain branch is connected to the antenna. This feature allows minimising thenumber of antennas and external combiners, as only one of the branches isconnected. For example, two PrimeSites can be connected to one single antennaby using one external combiner.





2.46 12-TRX cell with RTC dual duplexing

Capacity features such as IUO and FH give operators more possibilities to usehigher capacity configurations. The introduction of Dual Band sets alsorequirements for increasing the number of TRXs in a BTS.

At the moment, the maximum configuration for a Nokia Talk-family BTS withRTC is 6+6 TRXs with one BTS and 6+6+6 TRXs with two BTSs. This is due tothe combiner solutions. In the current product architecture, the internaldimensioning and design solutions have been done from the viewpoint that 12 isthe maximum number of TRXs that are supported under one BCF. By modifyingthe combiner solution, it is possible to build high-capacity sites with up to 12+12+12 TRXs by installing BTSs side by side.

The dual-duplex RTC solution increases the BTS capacity up to 12 TRXs percell. There are two different solutions available depending on the number ofantennas in use. The number of antennas can be minimised by using twoadditional 3 dB splitters to divide the main and diversity receive signals betweenthe RTC duplex filter and RMU units. In this case, only two antennas are needed.The use of splitters causes 3 dB degradation in RX sensitivity, but this can becompensated by using MastHead Preamplifiers if necessary.

Alternatively, there is a four-antenna solution. By using four antennas, 3 dBsplitters are not needed at all and therefore there is no degradation in RXsensitivity. Two additional antennas are needed for the diversity RX branches.

If RTC got faulty in previous software releases, all TRX faults in those TRXswhich where connected to faulty RTC, recovered one by one. This enabledunnecessary TRX recoveries.


2.47 Variable DL Power Control

The BSC has a variable power change step size for increasing and decreasing theMS transmission power and for increasing the BTS transmission power. This isused in situations where the required power change is so large that by using thefixed power change step size, the power change would require several powercontrol commands and take a long time. Using the variable power change stepsize, it is possible to reach the required power level in one go.



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The existing downlink power control mechanism does not adapt to theenvironment adequately. Therefore, a modification is required to ensure thatoptimal DL power control is applied to the network and maximum capacity gainfrom FH can be acquired.

Variable DL power reduction step size

The current DL power control algorithm steps the power down by only a fixedreduction step. However in some situations more aggressive power reductions areneeded. The feature calculates the reduction step sizes according to the currentsignal strength and quality of the connection. Therefore, if the level of the signalstrength is high enough, or if the quality is excellent (BER 0), larger reductionsteps (even 6 dB) can be used. Otherwise normal reduction steps are used.

The variable power step algorithm adapts to the current radio environment fasterthan the normal one and therefore it decreases the overall interference, becauseunnecessarily high BTS transmission power is not used.

For more information, see RF Power Control and Handover Algorithm.


2.48 Mobile Station capability indication

Distribution of the MSs in the network is a significant factor when operators aredealing with capacity issues, network planning or introducing new services.Operators have a need for the information on how the MSs with diversecapabilities are distributed in the network.

MSs with various functions and capabilities are roaming in the network. Whenthe operator has precise knowledge of these MSs and their locations, the demandon the resources required by the different types of MSs can be taken into accountduring network planning.

The purpose is to provide cell specific information on the capabilities of the MSs.In this measurement, MSs are separated into groups based on revision level,supported frequency band and multislot capability.

Revision level

The MSs can be distinguished with the aid of the revision level. This informationshows if the MS is phase 1 or phase 2 type. In the MS capability indication thenumber of TCH reservations and the cumulative MS reporting times of the MSsof different revision levels are measured.




Frequency band support

The MSs can support different frequency bands. It is possible to distinguish fivedifferent types of mobile stations:

. Single Band GSM 900 MS

. Extended Band GSM 900 MS

. Single Band GSM 1800 MS

. Dual Band MS

. Tri Band MS

In the MS capability indication, the number of TCH reservations and thecumulative MS reporting times of the MSs supporting the different frequencybands are measured.

Multislot capability

In this MS capability implementation, the multislot classes from 1 to 18 areseparated. The number of TCH reservations for all these classes is measured.Also the total number of TCH reservations of both multislot capable andincapable MSs are measured.

This information can be used in network planning when the demand on theresources required by the different types of MSs is evaluated.


2.49 Automated Planning

This feature is targeted to increase the automation and planning accuracy in themobile networks. This reduces the operational costs and increases the revenues ofthe operator.

The target areas for automation in planning

By employing a high degree of automation it is possible to reduce the operatingcost associated with running a network that grows both in size and in complexity.In the future automation of the network will be one, if not the main enabler thatallows operators to reduce operating costs and thus gain a competitive advantage.



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The aim is to automate those tasks that have the largest impact on networkperformance and those that required the highest manpower. In addition, it is notonly aimed to automate existing methods, but also to improve these methods inorder to provide network quality improvements.

In GSM systems, the areas to which automation is applied are:

. frequency planning

. neighbour planning

. adaptive setting of parameters on a cell-by-cell basis

In order to obtain the maximum gain from network features such as IFH, allsupporting tasks have to be mastered at first.

By providing operators with the tools that enable the automation of networkplanning / optimisation tasks the following targets are reached:

. improve network performance

. reduce operational costs (OPEX)

. reduce need for highly trained personnel

. speed-up implementation times of new features

During S10 time frame one new BSC measurement was created. Thismeasurement, Defined Adjacent Cell Measurement, complemented the S9Channel Finder Measurement by providing the required information forfrequency and neighbour planning for the defined adjacencies of all BTS on aBSC.

The need for increased automation in mobile networks

Since the introduction of GSM the number of installed network elements (TRX,BTS, BSC, etc) has increased manyfold. Today, a trend for cellular networks is acontinuously growing number of base stations and transceivers. Fuelled by thecontinuing growth of subscribers and the uptake of new services, the amount ofinstalled hardware is continuing to increase rapidly over the coming years. Inorder not to sacrifice network quality operators used to increase the number ofpersonnel to cope with the increased requirement of the growing network.

However, it is impossible to continue increasing the number of personnel in linewith the increase in hardware. In addition, packet switched data services on 2ndgeneration mobile systems is being introduced via features such as GPRS andEDGE. The introduction of these features requires the dedication of key




personnel from the operator to address the design needs of these features. Withthe imminent deployment of 3rd generation of mobile systems (WCDMA) itbecomes clear that a different approach is needed to cope with the requirementsof the growing complexity of cellular networks.

The need for increased accuracy in planning networks

With the increasing introduction of cells that cover small geographical areas suchas microcell and picocells it is important that the accuracy of the frequency plan isincreased to ensure adequate call quality in each of these cells. However, currentmethods to create the frequency plan for these cell types have generally notimproved and are virtually identical to those used to plan macrocells. Thus, theexisting approach leads to inadequate call quality unless a high number offrequencies are dedicated to these cell types.

In order to improve the quality of the frequency plan for all cell types, mobilemeasurements replace inaccurate propagation predictions to build the InterferenceMatrix on which the frequency plan is based.

The above figure displays the conventional approach of using propagationpredictions to create an interference matrix and subsequently a frequency plan.

Example of Automation: Frequency Planning

To provide insight on how automation can be applied to one of the above-mentioned area, an example on the automatic creation of a frequency plan in aGSM network is presented.

This principle can also be applied to other areas of automation such as neighbourplanning and the adaptive setting of parameters. The closed-loop approachenables the setting of parameters on a cell-by-cell basis and thus helps providingoptimum performance. Attempting to manually parameterise on a cell-by-cellbasis is almost impossible due to the manpower required. This approach can beapplied to a large number of parameters thus further increasing networkperformance when compared to the traditional approach of using globalparameter settings. Furthermore, what is required to apply this method is todecide on the relationship between a KPI, (Key Performance Indicators) that isbeing monitored and the parameter that is controlling the KPI. Once therelationship is established it can be applied to all cells. Moreover, by providingseveral different relationships between two values, it is possible to havecustomised parameter settings for certain cell types or certain geographical areas.




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2.50 Synchronised Base Station Subsystem

This feature is considered to provide the enabling synchronisation functionalityrequired for other key functionality, such as Dynamic Frequency and ChannelAllocation, to be developed. However, it also brings some direct performancebenefits and gives more accuracy for MS Location functionality. There aredifferent levels of synchronisation that can be implemented in a GSM system.Currently the achievable synchronisation in a GSM system is limited to thesynchronisation of the cells (BTS) belonging to the same site. This is possible asthe different logical cells within use the same existing site "master clock".

If all the clocks of the different sites along the network were synchronised, a"Network Level Synchronisation" would be achieved. This is the type ofsynchronisation achieved with the Synchronised BSS feature. The most effectivemethod to achieve this level of synchronisation is via GPS time reference. Thistime reference is acquired via the Location Measurement Unit, which supportsboth the Location and Synchronisation functionality.

Additionally, once the Network Level Synchronisation is achieved, further levelsof synchronisation are achievable by the control of the TSL number alignment(TSL Alignment Synchronisation) and the Frame Number (FN) used in everysite.

The synchronisation achieved with the BSS10 Synchronised BSS feature is theFrame Number (FN) Synchronisation. This synchronisation guarantees thatconnections in different cells are aligned and hence synchronised in a burst level.The FN used by different sites may be different. These FN values can becontrolled by the FN offset parameter to ensure maximum performance.

Performance benefits

Even though this functionality has been classified as an enabling functionalitysome immediate performance benefits are achieved when a system issynchronised.

. Higher location accuracy

. More stabile reference clock for the base stations

. Higher tolerance to interference

When a burst is causing interference to a serving connection, the FER (FrameErasure Rate) degradation of the serving connection increases as the interferingand serving bursts overlapping increase. When the overlapping is low, below20%, the degradation is small.




When the overlapping is above 40%, the training sequence starts to be affected,and the degradation starts to become equivalent to the one with full overlapping.

This means that the worst performance case is the 50/50 case (two servingconnection bursts being 50% interfered by the interfering burst), because in thatcase there is more than 40% overlapping in two consecutive timeslots. Theinterference is effectively twice as large as when the whole burst (or more than80%) is interfered.

Simulation results have shown that in a synchronised network the overall gainover the network is of 0.5 dB. This means that the network FER (Frame ErasureRate) versus C/I performance will be shifted by 0.5 dBs.

The control of the Frame Numbers of different cells provide the ability tomaximise the BSIC decoding mechanism of the mobiles in the system. Thereselection and handover processes can be enhanced by diminishing the problemsassociated to the often too slow BSIC decoding mechanism (especially in veryfast changing propagation environments such as indoors).


2.51 FER Measurement

FER Measurement provides the ability to report the UL FER from the BTS to theBSC. This provides more realistic measure of voice quality in the system andenables to perform handovers and power control based in FER rather than BERbased RxQuality. This feature can then provide more capacity and better quality.

Additionally, DL FER is estimated using the correlation between UL FER andUL BER values and applying these to the DL BER values. Both UL FER valuesand estimated DL FEP (Frame Erasure Probability) values are available in thenew FER measurement. In addition to handover and power control algorithms,FER Measurement provides also significant improvements to network qualitystatistics.

Frame Erasure Rate is the best available indicator in a GSM system to assess theVoice Quality provided in a network. It represents the percentage of frames beingdropped due to high number of non corrected bit errors in the frame.

The BER figure currently reported to the system is not a good indication of thequality of the network, especially when efficiency of the error correctionmechanism changes due to functionality introduced in the network such asFrequency Hopping or Dynamic Channel Coding.



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Frequency Hopping spreads out the fading and interference problems, effectivelyallowing the decoding mechanism to restore the original information via the ErrorCorrection process. Not only the correlation between BER and FER change whenFrequency Hopping is in use but different frequency hopping schemes(depending on the reuse and number of frequencies to hop over) have a differentBER to FER correlation.

The Channel Coding algorithm in use has a direct impact in the Error Correctionperformance. Depending how robust the channel coding is, it associatedperformance varies. A clear example of this takes place when different codingschemes are implemented simultaneously in AMR networks. Again thecorrelation between BER and FER changes, and this time it happens dynamicallyaccording to the conditions.


2.52 Adaptive Multi Rate Codec, AMR

Adaptive Multi Rate Codec (AMR) introduces a set of codecs and adaptivealgorithm for codec changes, and thus can provide significantly better speechquality and more capacity.

With AMR, a very good speech quality in full rate (FR) mode is achieved even inlow C/I conditions or increase the speech capacity by using the half rate (HR)mode and still maintaining the quality level of current FR calls. Optimalinterworking with power control and handover algorithms together with enhancedquality measurements (FER Measurement feature) provides full benefits andinterworking with prior Nokia top-of-the-world capacity features includingIntelligent Frequency Hopping (IFH).

The Adaptive Multi Rate (AMR) codec consists of a family of codecs (source andchannel codecs with different trade-off bit-rates) operating in the GSM FR andHR channels.

The idea behind the ETSI AMR codec concept is that it is capable of adapting itsoperation optimally according to the prevailing channel conditions.

Generic AMR description

AMR consists of 8 different speech codec modes with total of 14 channel codecmodes, which are listed in the table:




Table 2. Channel and speech codec modes for AMR

Channelmode

ChannelcodecMode

Sourcecoding bit-rate, speech

Net bit-rate,in-bandchannel

Channelcoding bit-rate, speech

Channelcoding bit-rate, in-band

CH0-FS 12.20kbit/s(GSMEFR)

0.10 kbit/s 10.20 kbit/s 0.30 kbit/s

CH01-FS 10.20 kbit/s 0.10 kbit/s 12.20 kbit/s 0.30 kbit/s


TCH/FR CH3-FS 7.40 kbit/s (IS-641)

0.10 kbit/s 15.00 kbit/s 0.30 kbit/s





CH8-HS 7.95 kbit/s (*) 0.10 kbit/s 3.25 kbit/s0.10 kbit/s

TCH/HR CH9-HS 7.40 kbit/s (IS-641)

0.10 kbit/s 3.80 kbit/s0.10 kbit/s

CH10-HS 6.70 kbit/s 0.10 kbit/s 4.50 kbit/s0.10 kbit/s




(*) Requires 16 kbit/s TRAU. Therefore it is not seen as a feasible codec modeand will not be supported by Nokia BSS10.



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Codec mode adaptation for AMR is based on received channel quality estimationin both the MS and the BTS, followed by a decision on the most appropriatespeech and channel codec mode to apply at a given time. In high-error conditionsmore bits are used for error correction to obtain error robust coding, while in goodtransmission conditions only low amount of bits is needed for sufficient errorprotection and more bits can, therefore, be allocated for source coding.

An inband-signalling channel is defined for AMR that enables the MS and theBTS to exchange messages on applied or requested speech and channel codecmodes. The above mentioned selected speech codec mode is then sent, by usingthe inband signalling channel, to the transmitting side, where it is applied for theother link. BTS commands the MS to apply a particular speech codec mode in theuplink, but MS can only request BTS to apply a particular speech codec mode inthe downlink because BTS has an option to override the MS's request.

An MS supports all speech codec modes, although only a set of up to 4 speechcodec modes is used during a call. BSC supports all of speech codec modes,except 7.95 kbit/s on HR channel, and it has one default set for each channelmode. The default codec sets include also a default set of decision thresholds andhysteresis. The initial codec mode and codec set with thresholds and hysteresisare transferred between network elements and MS by using the existing layer 3signalling, the basic principles for EFR are reused. Only a few add-ons areneeded.

The AMR system makes use of the inband signalling for the link adaptation, foreach codec mode set there is an associated set of decision thresholds for mappingthe channel quality measurements to the Mode Commands/Requests.

Link adaptation (LA)

There are two link adaptation (LA) modes; the ETSI specified fast LA and theNokia proprietary slow LA. Fast LA BTS allows inband codec mode changes onevery other TCH frame, but in Nokia proprietary slow LA BTS allows inbandcodec mode changes only on SACCH frame interval. During both LA modesBTS indicates the first and the last used codec during the last measurementinterval and the average quality. Reactions are the following in Rx quality casesof power control (PC) and handover (HO) algorithms in BSC:

. If the quality is below lower thresholds then PC (more power) or HO istriggered depending on the current threshold values. Otherwise if quality isabove lower thresholds, nothing is done.

. Respectively, if the quality is above upper thresholds then PC (less power)is triggered. Otherwise if quality is below upper thresholds, nothing isdone.

Above cases are valid only in quality HOs, not for example in power budget HOs.




All the information (codec usage and quality) goes to BSC statistics part forfurther processing.

BSC indicates to BTS about which LA mode is used. Fast LA is the default modeof BSS. The octet defining the LA mode used shall not be sent to MS by BTS.

Initial codec mode selection by BTS and MS at call set-up and handover

The Initial Codec mode to start the speech coding operation at call set-up andafter handover may be signalled by layer 3 signalling, in which case it shall beused by BTS and MS.

If the Initial Codec mode is not signalled, the Initial Codec mode, which is usedby BTS, and MS is given by the following rule. If the codec mode set contains:

. 1 mode, then it is the Initial Codec mode

. 2 or 3 modes, then the Initial Codec mode is the most robust mode of theset with lowest bit rate

. 4 modes, then the Initial Codec mode is the second most robust mode ofthe set with second lowest bit rate

Channel allocation depends on the parameter Initial AMR channel rate, whichdefault value is Any Rate. Any Rate means that the chosen channel rate is definedby taking into account the currently used information (Channel Type IE, resourcesituation on radio interface, circuit pool, current channel rate, handoverparameters, etc.). The other option is AMR FR, which means that full ratechannel is allocated despite of the values of the currently used information. IfAMR FR cannot be allocated, then allocation is continued with the currently usedinformation. Parameter is valid in call set-up (except FACCH call set-up), internalinter cell handover and external handover.

The reason behind this parameter is that quality may not be sufficient for HRAMR call set-up (radio measurement is done on SDCCH).

AMR capable TRXs are allocated first for AMR speech call use and then forother speech calls.

RxQual thresholds

New RxQual thresholds are specified for FR and HR AMR sets. Default valuesfor these new thresholds are set according to the default AMR codec sets. CurrentNx and Px values of RxQual thresholds are used.



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If the operator wants to replace or remove a most robust mode on AMR set, thecorresponding PC and HO RxQual thresholds has to be edited manually. Thisalso applies to the least robust mode. Replacement or removal of a middle modeon AMR set does not effect on the new PC and HO thresholds.

Handovers between FR AMR and HR AMR

New RxQual HO thresholds are specified for FR and HR AMR and they aretaken into account when making intra-cell handovers between FR AMR and HRAMR:

. intra HO threshold Rx qual for AMR FR

. intra HO threshold Rx qual for AMR HR

Current Nx and Px values of RxQual thresholds are used.

Packing of FR AMR calls to HR AMR calls due to cell load

Spontaneous packing of FR AMR calls to HR AMR calls is triggered when thecell load is high enough, the number of free full rate resources reduces below thevalue of the parameter Lower limit for FR TCH resources (according to the BTSlevel parameter, if it contradicts with the BSC level parameter). Packingcontinues until the cell load is low enough, the number of free full rate resourcesincreases above the value of the parameter UpperLimitForFRTCH resources(according to the BTS level parameter, if it contradicts with the BSC levelparameter).

Spontaneous packing is triggered by any new channel allocation. BSC keepsrecord of the FR and HR AMR calls per BTS and corresponding counters areupdated during channel allocations and releases.

After a new channel allocation the BSC makes a request to perform an intra-cellHO for N amount of calls. N is defined by the BSC and it follows the principlethat the number of free full rate resources increases by one compared to thesituation before the new channel allocation. Packing request is done with a newunacknowledged procedure. BSC performs the ordered HOs for FR AMR calls,whose quality is above the intra HO threshold Rx qual for AMR FR and whichuse the least robust codec mode.

A packing request is valid until it is overwritten by a new one. A packing request,which indicates the amount N as 0, is used to remove any pending packingrequests.




Unpacking of HR AMR calls to FR AMR calls due to call quality

Spontaneous unpacking of HR AMR calls to FR AMR calls is triggered when thequality of a HR AMR call degrades below theintraHOthresholdRxqualForAMRHR . Cell load does not have an effect.

When Rx level is good, BSC performs intra-cell HOs for HR AMR calls one byone according to the new threshold. Otherwise inter-cell HOs are performedaccording to the current threshold parameters.

FR and HR AMR call counters of BSC are again updated during channelallocations and releases.

Prioritisation of AMR capable cells during internal and external handovers

In order to support AMR call continuation also after internal or external HO, thehandover target cell list is manipulated so that AMR capable cells, in which loadis low, are on the top. The candidate cells on the target list are already pruned bythe adjacent cell parameter HOMarginPBGT (PMRG).

AMR capable cells are verified by the new adjacent cell parameter AMR targetcell of direct access to desired layer and those AMR capable adjacent cells areprioritised that are below the threshold of BTS parameter BTSLoadThreshold(BLT). Prioritisation is only done when the AMR call is the current call type.

About finding the AMR capable cell in call set-up, see Direct Access to DesiredLayer/Band (DADL/B).

IFH and IUO

AMR specific good and bad C/I thresholds are specified for HR and FR AMR:

. super-reuse good C/I threshold for AMR HR

. super-reuse bad C/I threshold for AMR HR

. super-reuse good C/I threshold for AMR FR

. super-reuse bad C/I threshold for AMR FR

Current Nx and Px values of C/I thresholds are used.

The new threshold values for HR AMR serve also the basic HR.

The current good and bad threshold pair (super-reuse good C/I threshold andsuper-reuse bad C/I threshold) is going to serve the basic FR.



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With these thresholds operator can control, which type of speech calls arepreferred to enter the super layers cells, for example, HR AMR calls could bepacked to the super layer in order to increase the capacity of cells (good value forHR AMR, for example, - 5 dB (compared to the current value) and good value forFR AMR, for example, + 5 dB).

FER estimation

FEP, when available (FER estimation is optional), replaces RxQual in PowerControl and Handover algorithms.

Measurements

The last used uplink and downlink AMR codec mode in the last measurementinterval is added to the Handover Measurement and to the Power ControlMeasurement.

Direct access to desired layer/band (DADL/B)

In order to support 2nd generation BTSs in AMR environment, DADL/B is usedto handover AMR calls to co-located AMR capable cells during call set-up phase.Both intra and inter BSC DADL/B handovers are possible and preferably insideone frequency band as the failure probability is higher with DADL/B handoversbetween bands.

TCH assignment vs. DADL/B handover start:

. If AMR call is the aim and there are no TCHs available in the accessedcell, the Directed Retry (DR) due to congestion, with or without queuing,is made.

. If there are TCHs available in the accessed cell and there are adjacent cellsdefined as DADL/B handover target cells with the parameter AMR targetcell of direct access to desired layer, then the DADL/B handover is applied.Adjacent cells are not verified according to the MS capabilities (singleband, dual band or tri-band), but must fulfil the current signal levelrequirements in order to be considered as a target cell for DADL/Bhandover. The current method for sorting the target adjacent cells is used.

If there are no DADL/B handover target cells defined, the TCH is allocated fromthe accessed cell and another speech codec than AMR is chosen.




Default AMR codec sets for FR and HR

BTS-MML is used to take care of entering, modifying and displaying the newmultirate configuration, that is, AMR codec sets, for BTS. The AMR codec setmodification does not require the locking of BTS. The AMR set includes AMRcodecs, their threshold and hysteresis values and initial codec mode definition.The basic AMR set for FR channel on BSC:

CodecMode

Threshold(C/I)

Hyster-esis (C/I)

Lowerthreshold(C/I)

Upperthreshold(C/I)

BER (%) FER (%)

12.2 11 1 11 � 2.97 0.08

7.4 7 1 7 12 6.72 0.15

5.9 4 1 4 8 10.38 0.98

4.75 � 5

The basic AMR set for HR channel on BSC:

CodecMode

Threshold(C/I)

Hyster-esis (C/I)

Lowerthreshold(C/I)

Upperthreshold(C/I)

BER (%) FER (%)

7.4 14 1 14 � 0.62

5.9 11 1 11 15 1.08

4.75 � 12

Lower threshold in the tables above means towards more robust codec and upperthreshold means towards less robust codec.

Nokia AMR Solution

AMR codecs are supported by different Nokia base station generations asfollows:

. Nokia 2nd Generation Base Stations:

Nokia 2nd generation DE21 BTS will not support AMR.

. Nokia Talk-family Base Stations:



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Nokia Talk-family BTS has AMR support for FR modes 4.75, 5.9, 7.4 and12.2 as well as for HR modes 4.75, 5.9 and 7.4. With this approach, thelink adaptation between full scale of FR modes and almost full scale of HRcan be achieved.

. Nokia PrimeSite Base Station:

Nokia PrimeSite base station AMR support is similar to that of Nokia Talk-family base stations. Due to limited DSP processor/memory capacity thefrequency hopping functionality is removed from PrimeSite BTSs toenable this SW modification. This means that the last PrimeSite SWrelease supporting frequency hopping is DF5.0.

. Nokia InSite Base Station:

Nokia InSite BTS does not support AMR.

. Nokia MetroSite GSM and MetroSite EDGE and UltraSite EDGE BaseStations:

Nokia MetroSite and UltraSite base stations have full AMR supporthowever Nokia UltraSite EDGE TRXs have AMR support in CX3.1software release.

. AMR codecs support in Nokia BSC and TCSM:

All the Nokia BSCs have full AMR support. except 7.95 kbit/s on HRchannel. Nokia TCSM2/E has full AMR support.

. TC PCM pool type is needed for transcoder configuration in A-interface.At minimum the basic AMR type, which supports FR AMR and HR AMR(pool 23), is at least implemented. Support for other pool types is stillbeing studied.

. Submultiplexing on highway PCM is 8/16 kbit/s, for example, if AMR FR(16 kbit/s) is used in Abis interface, the Ater interface rate is also 16 kbit/s.

. Respectively, if AMR HR (8 kbit/s) is used in Abis interface, then Aterinterface rate is 2 * 8 kbit/s (BSC transmits ones (= bit value 1) on theunused 8 kbit/s sub-timeslot).

Nokia TCSM does not support AMR.

With the AMR HR implementation BSCs maximum channel capacity4096 must be taken into the account in BSCs TRX amount dimensioning.For example, the BSC2i provides with 512 full-rate TRXs capacity or 256half-rate TRXs.

BSC TRX capacity can be maintained by using FR to HR load thresholdparameters.

For more information, see Enhanced Speech Codecs in BSC.





2.53 Common BCCH Control

The Common BCCH Control feature allows the integration of resources fromdifferent frequency bands into one cell. TRXs of different frequency bands can beconfigured in the same cell by letting them share a common BCCH that has beenallocated from one frequency band used in the cell.

The feature enhances the functionality of a cell to offer service to multibandmobile terminals in all the frequency bands which they support. The featureprovides improved trunking gain, tighter reuse of GSM1800 carriers, betterquality due to the decrease in the number of handovers, and improved spectralefficiency.

A common BCCH of a cell is configured in only one of the bands of operationwhen resources across all bands are co-located and synchronized.

Common BCCH Control utilises the segment architecture. TRXs of differentfrequency bands are gathered as different BTSs within a cell and a cell of thiskind is called a segment.

Figure 7. Tri band Common BCCH

EGSM 900

GSM 1800

GSM 900



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Figure 8. Segment in Common BCCH

For more information, see Common BCCH Control in BSC and Dual BandNetwork Operation.


2.54 Dynamic Abis Allocation

Dynamic Abis allocation is a solution for higher data rates of EGPRS to ensurecost efficient and flexible Abis transmission capacity addition. The Dynamic Abisfunctionality allocates Abis transmission capacity to cells when needed instead ofreserving a full fixed transmission link per TRX.

As data rates per radio timeslot can vary between 8.8 and 59.2 kbps, traditionalstatic Abis allocation does not use transmission resources efficiently. TheDynamic Abis feature uses existing Abis more efficiently by splitting PCMs intopermanent timeslots for signalling and voice or data and a dynamic pool for data.The pool can be shared by a number of transceivers. The Dynamic Abistransmission solution saves up to 70% in the Abis transmission expansion cost asit allows Abis dimensioning to be performed near to the average data rates insteadof peak rates. This also applies to the number of 2M BSC interfaces needed.

Dynamic Abis is implemented as a software feature.The implementation ofshared transmission channel connection pools is supported by Nokia cellulartransmission cross connection products and made easy with the Nokiatransmission network planning tool.

Implementation of Abis channel mapping is arranged so that traditional (notEDGE) TRXs are connected normally to the BSC, with a 16 kbps point-to-pointlink from the TCH to the BSC. EDGE TRXs are configured slightly differently asthe basic capacity is reserved for signalling (TRXSIG, BCFSIG). The BSCallocates Abis capacity for calls (voice or data) from the pool when required. The

NEW:Cell = SEG

= several BTSs

OLD:Cell = BTS Talk GSM900

Talk GSM900

Ultra GSM900

Ultra GSM1800




capacity for calls can be reserved in 16kbps blocks. For every EDGE TRX thereis a fixed 16 kbps allocation for TRXSIG and in addition, capacity needed forcalls is reserved from the Dynamic Abis Pool. This Dynamic Abis pool can becommon for many EDGE TRXs located at various sites.

Maximum number of TRXs per Dynamic Abis pool is 32 due to signallingrequirements of BCSU unit.

Interworking with other Nokia features

ISDN Abis

ISDN Abis and Dynamic Abis allocation cannot be used together.

Optimised Abis allocation

Optimised Abis allocation becomes unnecessary, because the traffic channels areallocated on a call basis and since signalling links are fixedly allocated.

Satellite Abis

(E)GPRS utilizing the Dynamic Abis does not work with Satellite Abis due todelays in the satellite connections. Therefore there is no point in using DynamicAbis with Satellite Abis.

GPRS

GPRS territory method and EGPRS use the dynamic Abis.

Compatibility with base stations

BSS10.5 solution for the Dynamic Abis is compatible with Nokia MetroSite andUltraSite EDGE base station EDGE TRXs.


2.55 Chaining of Nokia MetroSite Base Station

Nokia MetroSite GSM and EDGE Base Stations can be chained in order to buildlarger configurations for microcellular environments and still have an easyinstallation and O&M functions. The chaining is done by synchronising a frameclock between base stations and extending internal D-bus. One transmission unit



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is saved for each extension cabinet. O & M functionality is centralised to themaster cabinet. Only one extension cable between cabinets is needed. Themaximum number of combined MetroSite Base Stations is three, and the totallength of a bus cable is limited to five meters.

If a slave base station loses its chaining interface, the TRX Faulty alarm isactivated for each TRX in it. The chaining is arranged such a way that the centrecabinet can be un-powered without any problem in case of three cabinetconfigurations.


2.56 New MS power levels

This feature is an extension to the MS power levels defined in phase 1 GSMSpecifications. These new power levels are defined in phase 2 TechnicalSpecifications. By allowing the MS to use lower transmitting power there isfewer interference to other calls. The interference is reduced specially in networkwith small cell sizes (in micro cells). This way the network provides betterquality.


2.57 Chained Cells in Rapid Field Drop

Chained Cells in Rapid Field Drop feature is designed to maintain calls in therapid field drop environment and is especially useful in the microcellularenvironment.

The chained target cells are used to select the most probable target cell(s) forhandover. Some of the handover parameters are adapted dynamically andautomatically in order to provide fast reaction.

Due to the complex nature of the microcellular environment, a turn-a-corner MScan cause problems. When a MS is turning a corner, the signal strength ofmicrocell may drop by 30 dB due to the lose of line-of-sight. The existing featureRapid Field Drop in Chained Cells direct an MS from horizontal cell to a verticalone, but it may also cause a ping-pong effect to the in-house slow-moving traffic,if the Rapid field drop threshold is set too high. That is the reason why the newultimate solution to the turn-a-corner handover is designed. The feature is calledEnhanced Rapid Field Drop.




The basic idea of Enhanced Rapid Field Drop (ERFD) improvement is to detect aDeep Dropping Edge (DDE) for serving cell signal and handover the call to thecorrect adjacent cell. The ERFD improvement is particularly designed formicrocellular networks where the signal strength of a MS can vary a lot. TheDDE algorithm is based on monitoring the continuos deep drop in the servingcell's signal strength (both uplink and downlink) and a few new handover controlparameters.

The adjacent cell evaluation after ERFD is made according to the normal targetcell evaluation, however shorter averaging windows are used to speed up thedecision process.



2.58 MS Speed Detection

The MS Speed Detection feature is designed to determine the speed of the MS inGSM 900/1800 networks so that the fast moving mobiles can be directed tomacrocells and the slower mobiles respectively to microcells, thus decreasing thenumber of handovers in microcells.

The MS speed detection is a joint operation between the BSC and the Nokia BTS.The role of the BTS is to measure the MS speed and to send the measured MSspeed information to the BSC by including the speed information in theMeasurement Result message. The handover decision algorithm in the BSCverifies the MS speed indications sent by the BTS. The adjacent cell layerdefinitions are used with this feature. If a MS is detected as a fast moving MS, itis handed over to a upper layer cell (macrocell) if any are available. The MSsdetected as slow moving mobiles are handed over to lower layer cells (microcells)if any available. The MS Speed Distribution Measurement is used to collectstatistics of the MS speed distribution on cell basis.

Varying Window size

The basic idea of the MS Speed Detection feature is to keep the fast moving MSsin macro cells and direct the slow moving MSs into microcells. However, someoperators have different strategies for traffic distribution. It is suggested not to useSpeed Information as a micro to macro handover indication because "Speed"itself has different interpretations in different locations. Therefore, it is reasonableto have variable window size ( Better Cell Trigger / Quality Trigger ) according tothe speed indication.



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In principle, high-speed MS should use shorter average window size, and low-speed MS should use longer average window size. Therefore, all averaging-processes should have two sets of widow parameters, one set for high speed MSand one set for low speed MS. By applying variable window size, fast-movingMSs have shorter window size and they may handover to target cell faster. For aslow-moving MS, a longer window size is applied in order to prevent it fromunnecessary oscillation.



2.59 Fast moving MS handling in macrocell

Fast moving MS handling in macrocell is designed to handle the fast movinghandheld MSs in macrocells and provide better service for subscribers in a 2-layer or multilayer microcellular network.

The network operator can define the adjacent cells to three different layers fromthe serving cell's point of view:

. lower layer

. same layer

. upper layer

These layer definitions can be used to direct MSs in hierarchical network as lowas required. The suitable layer selection can be based on the MS relative speed ina underlying lower level cell.

Several microcells are embedded in macrocell's area and they are defined asadjacent cells to the macrocell. When an MS is served by the macrocell, it movesthrough the coverage area of the microcells and starts receiving signal from anadjacent microcell. After operator defined time (when the MS is in the coveragearea of the adjacent micro cell) if the signal level of the adjacent micro cellexceeds the minimum signal level (defined per adjacent cell) and the adjacentmicro cell is lower layer cell the MS is handed over to the micro cell.






2.60 C2 microcell reselection

The C2 MS idle mode cell re-selection parameter allows fast moving mobiles abetter way to select a cell through which they might expect to receive bestservice. The C2 is useful in micro cellular environment and also in case of GSM900/1800 dual band. The dual band MS can be forced to select GSM 1800 cellwhen available.

For more information, see Dual band Network Operation and Basic Call .


2.61 Multi BCF Control

Multi BCF Control feature allows the combination of several BTSs into onelogical cell, allowing the operator to increase the capacity of a cell whilemaintaining the maximum spectral efficiency. The feature increases the cellcapacity for Nokia Talk-family BTSs to 24 TRXs and for Nokia UltraSite EDGEBTSs to 36 TRXs while requiring no extra BCCH. Multi BCF also provides apath for site expansion from Nokia Talk-family to Nokia UltraSite EDGE BTS,and therefore, an evolution path to EDGE services.

An operator can arrange base stations so that TRXs in different base stations(operating on the same frequency band) can serve the same cell with singleBCCH. At the BSC operator uses a segment (SEG) object where operator sets allBTS objects sharing the same BCCH.

A Nokia Talk-family Base Station can be upgraded to EDGE by installing aNokia UltraSite EDGE Base Station with EDGE-capable TRXs on the site as anextension cabinet. Site compatibility is achieved by synchronising these two basestations and using existing antenna and feeder structures. They share a singleBCCH (per sector) and function in the network as a single cell. This is valid whenTRXs are on the same frequency band. Common BCCH optionality is needed ifTRXs from different frequency bands are needed to be operated on a single cellconfiguration with common BCCH.

In this configuration, the Nokia Talk-family transceivers serve voice, 9.6 data,HSCSD and GPRS. In addition, Nokia UltraSite EDGE Solution provides truemobile multimedia capabilities with EDGE.



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Figure 9. Segment in Multi BCF Control

For more information, see Multi BCF Control in BSC and Common BCCHControl in BSC.


2.62 Optimisation of the MS power level in handovers

Optimisation of the MS power level in handovers is a feature, which is designedto cut down the probability of high RF power peaks in the uplink after both intra-cell and inter-cell handovers and also in call setups and so reduce the uplinkinterference in the radio network.

The BSC determines which RF power level the MS that has been handed overuses as the initial RF power in the target cell in inter-cell handover. The RF poweris determined for the serving cell in case of intra-cell handover and in call setup tobe used as the initial RF power. The default initial RF power level is themaximum RF power that an MS is permitted to use on a traffic channel in thetarget cell but, in case of an intra-BSC handover and call setups, the BSC is alsoable to optimise the initial RF power level so that the RF power level is lowerwhen the radio link properties of the target cell / serving cell are good. Theoptimisation is based on downlink signal level of the adjacent cell and operatordefined parameters (as per adjacent cell).



Onecell Talk TRX

OLD:Cell = BTS

NEW:Cell = SEG

=several BTSs

Talk TRXUltra TRX




2.63 High Capacity Signalling Links on A interface

The GSM network has been originally specified (GSM 08.08) and designed touse 64 kbit/s CCS7 links in the A-interface. Due to various reasons, the CCS7links can be congested in the A-interface. The situation could be improved withhigher capacity CCS7 links on the A-interface.

Higher capacity CCS7 links (128, 256 kbit/s) between the BSC and MSC aresupported. They require the use of Nokia BSC2i with plug-in-unit AS7-V andNokia MSCi with plug-in-unit AS7-A.

Normally, there are 4 timeslots reserved for 64kbit/s CCS7 links. However, withhigh capacity CCS7 link feature, there are always 16 timeslots reserved for CCS7usage regardless how many timeslots are actually needed, so having high capacityCCS7 links on A interface may have impact on the maximum LapD capacity ofBSC depending on the configuration.

Table 3. Number of LapD links and CCS7 links per BCSU with or withoutHigh capacity CCS7 link for high capacity BSC

64kbit/s CCS7link

128 kbit/s CCS7link

256 kbit/s CCS7 link

MaximumNumber of CCS7links

4 4 4

MaximumNumber ofBCFSIG LapDlinks

32 32 32

MaximumNumber ofTRXSIG LapDlinks

64 64 64

Maximumnumber of LapDlinks (BCFSIG+TRXSIG+ISDN+ET-LapD)

124 112 112




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3 Coverage

The features and functionalities presented in the following sections are related tothe coverage of the Nokia BSS.


3.1 Enhanced Coverage by Frequency Hopping

This feature uses Frequency Hopping gain, especially the frequency diversitygain, to build coverage to radio network.

Frequency Hopping (FH) is mainly used to improve quality and capacity in thecellular network. However, it can be used to improve coverage as well. Due to thefrequency diversity gain provided by Frequency Hopping, the coverage of thecell can be increased, especially for slow moving MSs.

The gain that the frequency diversity delivers depends mostly on the number offrequencies included into the hopping sequence, and also on the environment. Ina rural area, a line-of-sight condition often exists and the multipath effect is notvery strong, therefore, the gain produced by FH is clearly lower than in a cityenvironment.

Because the Frequency Hopping gain depends on the number of hoppingfrequencies, Radio Frequency (RF) hopping is often the only way to achievemaximum gain, especially with low capacity sites. However, in RF hopping theBCCH transceiver cannot hop and therefore does not utilise the frequencydiversity gain. Although the BCCH channel itself is robust enough to providecoverage in the edge of the cell, the BCCH TCH timeslots are not providingextended coverage.

In order to utilise the Frequency Hopping gain for coverage enhancement, thechannel allocation and handover algorithm in BSS require modification.Therefore, Nokia is introducing a solution for enhancing coverage. The solutionprovides the network operators with the tools to intelligently improve thecoverage of their networks through FH and BSS SW features. Because the



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Coverage

hopping transceivers are providing more coverage than the BCCH one, thesolution handles the channel allocation to appropriate network layer. The solutionalso provides seamless handovers between two layers according to the path lossor quality of the connection.

For more information, see Enhanced Coverage by Frequency Hopping .


3.2 Improved solution for Extended Cell

The extended cell implementation is based on one BCCH and two TRX solution.Different TRXs serve normal area and extended area. The TRX that serves thenormal area is normally configured with the BCCH/SDCCH and TCHs. Thetiming of the receiver of the TRX that serves the extended area (E-TRX) has beendelayed so that it can serve the area beyond 35 kilometres. The time slot 0 of E-TRX is tuned to the BCCH frequency in order to get RACH-bursts from theextended area. The timing of transmitters is same in both TRX and E-TRX. Ifmore capacity is needed either in normal area or extended area more TRXs can beadded as required to serve those areas.

For more information, see Improved Solution for Extended Cell.


3.3 Intelligent Coverage Enhancement (ICE)

Intelligent Coverage Enhancement (ICE) is a solution where the same area orsector is covered by two cells with different output power and these two cellsshare common antennas.

Naturally, the coverage areas are not exactly the same because of the difference inpower, but it is characteristic of this arrangement that the coverage area of the cellhaving smaller output power is completely within the coverage area of highpower cell. Because of this it is possible to use common antennas for the two cellsand thus reducing the number of antennas required.

In locations where it is necessary to cover as large an area as possible with onecell a special configuration can be used. This feature makes it possible to have3dB more transmit power into the antenna connector.




The ICE solution is configured by using 3 TRXs. The first TRX is configured bybypassing the hybrid combiner that increases the output power by 3 dB comparedto the two other TRXs, that are combined together into an another antenna.

TRX1 is configured as its own cell with larger service area and TRX2 and 3 areconfigured then as an another cell with totally overlapping service area. TRX1has higher output power since the hybrid is bypassed, thus MSs are likely to campunder it. Because of this the SDCCH capacity must be allocated for the TRX1according to the needs of both cells. It is necessary to hand all possible calls to thelower power cell to save capacity for mobiles on the extended area. Umbrellahandover can be parameterised to take care of this. When moving away from thecell, handover to higher power cell takes place because of signal level and quality.Directed retry can also be used to share traffic between the two cells.

It is also possible to use two high power TRXs by having the hybrid bypassed inboth AFEs. Then the capacity is limited to two TRX/cell. In this case there is noneed to divide TRXs into separate overlapping cells as both TRXs have the samecoverage.

In the 'Handover support for coverage enhancement' the call is always initiated inthe coverage layer, but if the signal level exceed a predetermined threshold, thecall can be handed over capacity layer. On the other hand, if the signal level fallsbelow the threshold or the call suffers bad quality, the call is handed overcoverage layer. To have this enhancement, only one BCCH per sector should beconfigured.

The 'Intelligent coverage enhancement with AFE & RTC' enhancement allowsbuilding AFE & RTC ICE configuration that uses two antennas. With twoantennas maximum configuration becomes 6 TRX (= 1 coverage + 5 capacityTRXs).

In an enhancement 'ICE support for booster' the transmit booster can be usedtogether with non-boosted TRX with the help of ICE concept. From hardwareconfiguration point of view, this is equal to a dual duplex configuration where theother AFE is replaced with booster specific filter unit, AFH.

For the 'ICE support for Booster' the boosted and non-boosted TRXs have to beconfigured as separate cells each with their own BCCH. For this reason'Handover support for coverage enhancement' is not supported with 'ICE supportfor Booster'.

ICE+ Configuration

ICE+ is a single cell with BCCH only, and defined in both the BTS and BSC as asingle cell. Thus, no separate BCCH is needed for the low-power TRXs. Thismakes frequency planning much easier and provides an extra traffic channel forthe low-power TRXs.



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These configurations extend the capacity of ICE configured sectors to two TRXswith combiner bypassed (high power TRXs) and two or four TRXs (low powerTRXs), which are combined in pairs by wideband combiner(s). The high-powerTRXs use an AFT filter unit, which has no combiner. This gives 3 dB highertransmitting power than the low power TRXs, which use one (for two TRXs) ortwo (for four TRXs) AFE filter units. This results in a combination of goodcoverage from the high power TRXs and high traffic handling capacity becauseof the total of up to four or six TRXs in one cell.

There are three basic variants of the configurations:

. 2 TRXs/AFT + 2 TRXs/AFE, 3 Antennas

is used where a minimum number of antennas are needed. Two antennasare used duplexed for both Tx and Rx, one antenna is used for Tx only.MastHead Amplifiers (MHAs)are needed for link balance.

. 2 TRXs/AFT+2/4/6/8 TRXs/1-4 AFEs, 4/5/6 Antennas or 2/3 Cross-PolarAntennas

is used where easy expansion to 2 + 4 TRXs is to be allowed for, or wherefour antennas are to be used, for instance where cross-polar antennas areused. All antennas are used duplexed for both Tx and Rx. MastHeadAmplifiers (MHAs) are needed for link balance on the AFT, and may beused with the AFE.

. 4 TRXs/2AFTs + 2/ TRXs, 6 Antennas or 3 Cross-Polar Antennas

is used for the maximum capacity.

In addition, AFE +AFE with hybrid pass can be one configuration for ICE+ aswell.

Multi-sector use

With extension cabinets, CityTalk and IntraTalk BTSs support up to three sectorswith two high-power and two low-power TRXs each, producing a total of 12TRXs.

Similarly, CityTalk and IntraTalk BTSs with extension cabinets support twosectors with two high-power and four low-power TRXs each, producing a total of12 TRXs.

This ICE configuration is a sector solution; all other sectors can have whateverconfiguration is necessary.

Network aspects




The BCCH carrier must be in one of the two high-power TRXs. The feature'BSS7021 Preferred BCCH TRX' must be used to ensure this. The SDCCHchannel must also be in one of the two high-power TRXs and have sufficientcapacity to cover all the TRXs in the cell.

Also, with the single BCCH, all the low-power TRX frequencies can be allocatedwith a high (non-BCCH) frequency reuse factor and the IUO (super-reuse)feature can also be used.

The handovers within the cell (between high power and low power TRXs) andbetween the ICE cell and neighbouring cells will be controlled by the normalBSC handover features. "Handover support for coverage enhancement" can beapplied to ICE+.

For more information, see Enhanced Coverage by Frequency Hopping.


3.4 Mast Head Preamplifier

A Mast Head Preamplifier (MHA) is used to compensate losses at the BTSreceiver antenna cable. Depending on the actual network uplink/downlinkbalance this feature allows an MS to use lower transmitting power, and thusincreases the MS battery lifetime or simply increases the size of the cell. TheNokia MHA provides gain in the range up to 12 dB. The BTS provides electricalpower for the MHA up to 150 mA at 11.5 V (11.1...12.4 V). DC power isprovided on the centre pin of the antenna port, positive with respect to ground.

The MHA has a special RF bypass relay, which can be used for two purposes.First, for the duration of the antenna VSWR measurement, it is necessary tobypass the MHA for correct result. Secondly, if a malfunction is detected in theMHA, it can be bypassed with this relay. Thus the service can continue withreduced capacity until service takes place.

In case of receiver diversity but no duplex filter both receiver branches can havetheir own mast head preamplifiers. If a duplex filter is used, the MHA can be usedonly in the diversity branch. No hardware or software modifications are requiredfor the BTS because of the installation of the MHA, only the appropriate entryinto the hardware database.

Nokia has a selection of products for all frequency bands that can be used induplexed antenna line too.




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3.5 Receiver diversity

Receiver diversity can be used to minimise local drops in the RF field strength.These drops are caused by multipath propagation, and can reduce the quality ofthe received signal, especially when the MS is near the cell border.

The principle of spatial diversity is to use two antennas for received signals. Theantennas are placed physically apart so that the correlation between receivedsignals is minimised. This way it is probable that when one receiver branchsuffers a field drop, the other is able to receive a signal with sufficient quality.The two separate paths are then processed in the baseband section of the BTStransceiver. A post detection weighted summing method is used to combine thesignals of the two branches.

In the Nokia 2nd generation diversity may be configured on a TRX basis to theOMU HW database (diversity on/off field per CU). This enables the user to havediversity in one sector while other sectors operate without diversity.

In the Nokia Talk-family the use of diversity can be selected on a sector basis intothe HW database.

The use of receiver diversity in the Nokia PrimeSite can be configured by thehardware database. Receiver diversity is available on the Nokia Talk-family andPrimeSite basic configuration.


3.6 TRX transmit booster unit

The TX transmit booster increases the typical output power of the BTS from 39.5dB to 46.5 dB (measured at the antenna connector). A TRX transmit boosterenhances downlink performance, and is used to balance the link in a downlinklimited situation. In addition, the TX transmit booster increases the cell size.

A booster unit is of the same size as a regular TRX unit and is located inside theBTS cabinet to a TRX slot. The maximum configuration with boosted TRXs is 1+1+1 in one cabinet and 2+2+2 in 2 cabinets.

In areas where more than 2 TRXs are needed in a cell, configurations like 3+3TRXs, 4+2 TRXs, or 6 TRXs at one site are supported. Larger configurationssuch as 3+3+3 or 4+4+4 TRXs can be achieved by using this feature and NokiaTalk-family BTS synchronization feature.




A filtering unit (AFH), is needed to accommodate for the higher output power ofthe TRX. Booster alarms are routed through AFH.

Note

When the 'ICE support for booster' is in use, the boosted and non-boosted TRXshave to be configured as separate cells each with their own BCCH. For thisreason the handover support for coverage enhancement is not supported with 'ICEsupport for booster' feature.


3.7 GSM/EDGE 800

This feature supports the use of 800 MHz frequency band in BSC.

For the 800 MHz band, the system operates in the following frequency bands:

Uplink: 824 - 849 MHz: mobile station transmits, base station receives.

Downlink: 869 - 894 MHz: base station transmits, mobile station receives.

The carrier frequency is designated by the absolute radio frequency channelnumber (ARFCN). FI (n) is the frequency value of the carrier ARFCN n in thelower band and Fu (n) the corresponding frequency value in the upper band.

All the existing BSS features are supported in 800 MHz band.




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Coverage

4 Data � IP Multimedia

The features and functionalities presented in the following sections are related tothe data and IP multimedia of the Nokia BSS.


4.1 High Speed Circuit Switched Data (HSCSD)

The High Speed Circuit Switched Data (HSCSD) feature provides accelerateddata rates for end-user applications. A current trend is for increased demand forhigh data rate applications like the World Wide Web (www), file transfer andfacsimile.

The BSS implementation reserves a multiple set of basic (current) resources forone high speed data call. The data rate and number of reserved time slots variesbetween one and user application defined maximum. The variable rate is needed,for example, for handovers to a new cell if the requested data rate cannot be givenright away. The BSS implementation of HSCSD supports simultaneous usage of4 timeslots per HSCSD call. The following table presents correspondingmaximum data rates with different channel codings:

RTSLs 9.6 kbit/s 14.4 kbit/s

1 9.6 kbit/s 14.4 kbit/s






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Both asynchronous and synchronous bearer services and transparent and non-transparent data services are supported. Transparent HSCSD uses a fixed data ratethrough the call but non-transparent is flexible and the data rate can be changedduring the call, for example, due to traffic situation. Radio interface is eithersymmetric or asymmetric according to the MS capability. However, Abis- and A-interfaces are always symmetric.

Support for an A-interface circuit pool(s) is required at MSC. BSC supportedHSCSD pools can handle all existing connection types and either maximum oftwo or four channel HSCSD connections. HSCSD pools are supported with andwithout 14.4 kbit/s channel coding capability.

In basic channel allocation consecutive timeslots are tried to be kept free formultichannel HSCSD connection. If there are not enough appropriate freechannels to fulfil the requested data rate, non-transparent HSCSD connection isstarted with less channels than needed. By resource upgrade procedure data rateof the HSCSD connection is risen, when appropriate channel is freed from otherconnection. If transparent connection can not be established in a cell, DR toanother cell can be tried.

At least one channel is allocated for non-transparent HSCSD call request, if thereis not a total congestion in the cell. In congested cell HSCSD load can be adjustedby parameterisation. Resource downgrade procedure is used to lower the HSCSDconnection data rate to give radio channels for other connections. Due to thenature of transparent service, the blocking for transparent service is highercompared to the non-transparent service.

This feature provides a fast way of transferring a huge amount of data within ashort time.

Pre-emption procedure is applicable for transparent HSCSD connections onlywhen it is a target for pre-emption release. If target of pre-emption is non-transparent HSCSD connection with more than one channel, handover or releaseis changed to resource downgrade.


4.2 Data services

This feature allows mobile subscribers to use wireless data transmissionconnections through the mobile network. Computers and faxes can be connectedremotely to the public data transmission network. The BSC passes controlinformation on channels to the BTS which, in turn, takes care of the transcoder.The RA1/RA1 function is used to convert the radio interface rates (12 kbits/s, 6




kbits/s, 3.6 kbits/s) at the interface between the channel encoder/decoder and rateadapter of the BTS and the CCITT V.110 80 bit frames of intermediate rates 8 and16 kbits/s on terrestrial links. This function is needed for all bearer services andnon-voice teleservices, transparent and non-transparent.

The MSC controls the channel type to be used for data transmission. Thefollowing data transmission speeds and types can be used: 600 bit/s, 1200 bit/s,2400 bit/s, 4800 bit/s, 9600 bit/s, 14400 bit/s.

The radio interface data rate 12 kbit/s can be used for the non-transparent service.

Note

Data channels over TCH/H are not supported.

At the top of this feature a 14.4 kbit/s GSM data service is built. This latestfeature is available in S7 release and provides an accelerated user data rate of 14,4kbit/s. This is done by changing the puncturing scheme.

Using of 14.4 kbit/s data service reduces cell coverage. For example, if thecurrent 9.6 kbit/s service has a 90 % coverage, the 14.4 kbit/s service has acoverage of about 84-87 %. Current threshold for power control represents thepredicted border of the acceptable user data performance for the speech or 9.6kbit/s data. This is not adequate for 14.4 kbit/s user data, since 14.4 kbit/s channelcoding can stand less errors. To maintain 14.4 kbit/s performance adequate, theRX_QUAL needs to be kept better and so the power increase has to be startedwith better quality for 14.4 kbit/s calls than other calls. A new thresholdparameter is defined for triggering downlink and uplink power increase for 14.4kbit/s connection. However, for optimal performance channel coding is changedbetween 14.4 kbit/s and 9.6 kbit/s channel codings by automatic link adaptation(ALA) procedure according to MS and BTS power levels. The parameterdetermines the MS and BTS power levels, when ALA is performed. ALA isapplicable for non-transparent data connections.

In A-interface 14.4 kbit/s data connection can be switched to one of the pools,which support 14.4 kbit/s channel coding




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4.3 GPRS functionality

Nokia offers a complete end-to-end General Packet Radio Service (GPRS)solution in the Nokia GPRS system, including GPRS core, network managementand charging gateway with high capacity, scalability and carrier class availability.As a part of the GPRS system, Nokia offers GPRS support in the BSS withpowerful radio resource management algorithms, optimised BSS networktopology and transmission solutions to ensure optimal investment to operatorsand high capacity and quality service for end users.

As data and internet services are the areas of growth in mobile communications, itis important for an operator to choose the right strategy in implementing thesesolutions. Mobile data is the key to opening the door to the high revenuecorporate sector and to value-added services for consumers.

GPRS is a major step forward in mobile data. It gives customers the benefits ofinstant IP connectivity on-the-move and of being continuously connected. GPRSprovides the possibility of being charged only for transferred data in addition tomore efficient use of limited air interface resources.

All Nokia BTSs support GPRS (channel coding schemes CS-1 and CS-2) withoutany hardware changes. The BSC requires Packet Control Units (PCU) to beinstalled into each BCSU unit to support GPRS.

GPRS provides packet radio access for a GSMMS. The benefit of GPRS is that itcan use the same resources that circuit-switched connections do by sharing theoverhead capacity. This means that one mobile uses the resources only for a shortperiod of time, that is, when there is data to send or receive. The sharing ofresources together with a very fast method of reserving radio channels makes theair interface usage even more efficient.

For more information, see GPRS in BSC and GPRS Handling in BSC .




Figure 10. GPRS network

Circuit-switched connections have traditionally been used in fixed networks forspeech and data. A circuit-switched connection occupies one line for the length ofthe connection. This is the optimum way of connecting to any data source if thereis a continuous data stream to be transmitted. Some applications such as video

MSC

SMSC

Firewall

LawfulInterception Gateway

(LIG)

BorderGateway(BG)

ChargingGateway(CG)

Firewall

LocalAreaNetwork

Server

Router

Corporate 1

Gateway GPRSSupport Node

(GGSN)

Billing/PrepaidServer

SS7Network

PSTNNetwork

Inter- PLMNnetwork

Serving GPRSSupport Node

(SGSN)

LocalAreaNetwork

Server

Router

Corporate 2

Firewall

Datanetwork(Internet)

BSCUm

BTS

GPRSbackbone network

(IP based)

Wap Server

Datanetwork(X.25)

R/S

Gi.IP

Gp Gi.X.25

Gn

SCP

HLR/AuCEIR

System

Billing



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transmission require a constant bitrate and transmission delay, and thus require acircuit-switched connection. Voice is usually transmitted over a circuit-switchedline - GSM voice and the current data services are based on circuit-switchedconnections.

Typical IT applications in Local Area Networks (LANs) and Wide Area Networks(WANs) use packet-switched connections. For example, when browsing theInternet, the user typically sends a request to a server, which replies. Afterdownloading the desired information, the user leans back to enjoy the content.During this reading or content-processing period, no data moves over the dataconnection. In a circuit-switched system, the line is still occupied although nodata is transferred. In a packet-switched system, the resources are released, so itcan be used by other subscribers. When the user is ready to receive new data, theterminal sends a request. The resources are reserved for the time required fortransmitting the request and initiating a second data transfer.

The data to be transferred is encapsulated into short packets with a headercontaining the origin and destination address. The packets are then sentindividually over the transmission network. Packets originating from one usermay take different routes through the network to the receiver. Packets originatingfrom many users can be mixed, so that the transmission capacity is shared. Nopre-set time slots are used. Instead, network capacity is allocated when neededand released when not needed. This is called statistical multiplexing, in contrastto static time division multiplexing. In static time division multiplexing, timeslotsare reserved for one user for the length of the connection, regardless of whether itis used or not, as with PCM lines and GSM voice and circuit-switched data.

GPRS upgrades GSM data services to allow interface with LANs, WANs, and theInternet. GPRS uses radio resources only when there is data to be sent orreceived, and is thus well adapted to the very bursty nature of data applications.Furthermore, it provides immediate connectivity and high throughput. Generally,any service that can be run on top of IP protocols (UDP or TCP transfer) issupported by the Nokia GPRS solution (taking into account data rate and delayrequirements).

WAP (Wireless Application Protocol) based services see GPRS as one carrier(UDP). Wireless Markup Language (WML) based services in GPRS can beaccessed using the standard WAP gateways. WAP is essential to createapplications that are 'useable' in the mobile environment (small screen display,low data rates).

While the current GSM system was originally designed with an emphasis onvoice sessions, the main objective of GPRS is to offer access to standard datanetworks such as LAN using TCP/IP protocol. These networks consider GPRS tobe a normal subnetwork. A gateway in the GPRS network acts as a router andhides the GPRS specific features from the external data network.




GPRS offers a very flexible range of bitrates to even over 100 kbit/s. Applicationsthat need less than one timeslot benefit from GPRS's ability to share one timeslotamong several users. Transactions such as credit card checks and a variety oftelemetric and telematic applications benefit from the fast session setup. Forexample, integrated GPRS mobiles in cars can be used for security purposes andall kinds of remote control and surveillance applications. The high bitrates thatGPRS provides give short response times, even if there is a lot of data to betransmitted.GPRS is the first GSM Phase 2+ service that requires major changesin the network infrastructure. This is because GSM is based on a circuit-switchedtransmission mode, and GPRS uses packet-switched connections. In addition tothe current GSM entities, GPRS is based on a number of new network elements.

. Serving GPRS Support Nodes (SGSN)

. Gateway GPRS Support Nodes (GGSN)

. GPRS backbone

. Legal Interception Gateway (LIG)

Along with the new network elements, the following functions are needed:

. GPRS-specific mobility management: the location of the MS is handledseparately by the SGSN and by the MSC/VLR even if some co-operationexists

. network management capable of handling the GPRS-specific elements

. a new air interface for packet traffic

. new security features for the GPRS backbone and a new cipheringalgorithm

. new MAP and GPRS-specific signalling

An investment in GPRS infrastructure is an investment in future services. GPRSpaves the way and is already part of the future third generation (3G) networkinfrastructure. Migration to 3G comprises deployment of the new WCDMA radiointerface - served by the GSM and GPRS core networks. Many of the future 3Gservices will be based on IP and GPRS Core network is the key step ofintroducing the IP service platform into the present GSM networks.

When migrating to the 3G services, preserving the Core Network investments is atop priority. Introducing UMTS complements the GSM network - by notreplacing it.




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4.4 GPRS in Nokia Base Stations

All Nokia BTSs support GPRS functions with software update so no separate sitevisits are needed.

Radio resources are allocated by the BSC (PCU). BCCH/CCCH is scheduled byBTS; messages are routed via TRXsig link between BTS and BSC. GPRS dataitself is transparent to the BTS; routed via TCH channels in Abis.

The CCU (Channel Coding Unit) in the BTS DSP performs the channel codingfor the following rates:

CS-1 (Channel Coding Scheme 1)- 9.05 kb/s

CS-2 (Channel Coding Scheme 2)- 13.4 kb/s

In Packet Transfer Mode, the MS uses the continuous timing advance updateprocedure. The procedure is carried out on all PDCH time slots. The mapping intime of these logical channels is defined by a multiframe structure. It consists of52 TDMA frames, divided into 12 blocks (of four frames) and four idle frames.


4.5 Optimised GPRS Radio Resource Management

This feature offers dynamic algorithms and parameters to optimise the use ofradio resources. Dynamic and flexible GPRS radio resource management isimportant in effective usage of the Air interface capacity to ensure the maximumand secure data throughput. The limited radio resources must be used effectively.

Note

In this feature the GPRS common control channels are combined with thecorresponding GSM channels. All the TCHs in a cell can be used as a PDTCH .




GPRS packets are sent uni-directional; uplink and downlink are separateresources. MS can also have bi-directional connection while using GPRS byhaving simultaneous uplink and downlink packet transfers. Temporary BlockFlow (TBF) is made for every new data flow. One or more packet data trafficchannels (PDTCHs) are allocated for the TBF. TBF is used to send RLC/MACblocks carrying one or more LLC PCUs. The TBF reservations of PDTCHs arereleased when all the RLC/MAC blocks have been sent successfully.

Packet Associated Control Channel (PACCH) conveys signaling informationrelated to a given MS. PACCH is a bi-directional channel and is located in thePDCH. It transmits signalling in both directions although data is transmitted(PDTCH) only to the assigned direction.

Multiple MSs can share one PDTCH, but the PDTCH is dedicated to one MS(TBF) at a time. This means that the PDTCH is reserved for multiple TBFs, butone TBF is receiving or sending at a time. All the GPRS TBFs allocated to aPDTCH are served equally. Quality of Service (QoS) peak throughput andpriority are not supported. The number of TSLs allocated for a multislot MS isdetermined by the MS multislot capability and network. Reallocations are donewhen transfer mode is changed between uni-directional (only uplink or downlinkdata transfer) and bi-directional (simultaneous uplink and downlink data transfer).

All the full rate or dual rate traffic channels are GPRS capable. With the NokiaGPRS solution the operator can define dynamically multiple parameters related tonetwork configuration, such as

. GPRS capacity cell by cell and TRX by TRX

. GPRS only traffic channels (Dedicated GPRS capacity)

. Default amount of GPRS capable traffic channels (Default GPRS capacity)

. Whether BCCH TRX or non-BCCH TRX is preferred for GPRS

The adjustable parameters help the network planners to control and optimise theGPRS radio resources.

The BSS is upgraded with enhanced RLC/MAC protocols and TRAU for theradio and Abis interfaces. Circuit Switched (CS) traffic has priority over PacketSwitched (PS) traffic. In a CS congestion situation, CS may use the DefaultGPRS traffic channels, but Dedicated GPRS traffic channels are reserved to carryPS traffic.

Default GPRS capacity determines a number of traffic channels (TCHs) whichare always switched to the PCU when allowed by CS traffic load. With theseTCHs the operator can supply the need for fast GPRS channel reservations for thefirst data packets. During peak GPRS traffic periods additional channels areswitched to GPRS use, if CS traffic load allows.



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Dedicated, default and additional GPRS TCHs form a GPRS pool consisting ofconsecutive radio interface timeslots. When the GPRS pool is upgraded, intra cellhandovers of CS connections may be needed to allow the selection of theconsecutive timeslot for GPRS use. New CS connections may be allocated to aTCH in the GPRS pool only when all the TCHs not belonging to the GPRS poolare occupied.

IUO super reuse and extended cell radius frequencies are not used for GPRStraffic, but the features themselves can be used to release resources for GPRSusage. In cells where Base Band Frequency Hopping is in use TSL 0 is not usedfor GPRS traffic.


4.6 Cell selection and re-selection

There are no handovers as such in GPRS. Instead there is cell re-selection. Thecell is selected autonomously by the mobile. The parameters used by the mobilefor cell re-selection are sent from the network and can be different for each cell.

This is implemented by supporting Network Control Order NC0. It means thatthe MS does not send neighbour cell measurements to the network and the MSinitiates the cell change in idle and transfer mode.

Path loss criterion (C1) and cell re-selection criterion (C2) can be used to controlMS cell selection.


4.7 Power control

Uplink power control is managed with a formula

PCH = min(G0 - GCH - a*(C + 48),PMAX)(1)

The operator is given cell specific parameters a and GCH used in formula (1).

GCH ("gamma_ch") determines the minimum MS output power and a ("alfa")determines the slope by which the downlink RX_LEVEL affects the power.




Downlink power control support is not included in the first GPRS release. This isa feature candidate for future BSS release.

The power of each block needs to be sufficient for two MSs:

. the MS receiving the data

. the MS receiving the USF flag (Uplink State Flag, determines uplinktransmission turn in case several mobiles have been assigned to the sameuplink PDTCH.)

By the current ETSI specifications, the uplink MSs receiving the USFs in thedownlink direction are not reporting any measurements


4.8 Coding Scheme (CS) selection

GPRS provides four coding schemes, from CS-1 to CS-4, offering data rates from9.05 to 21.4 kbit/s per channel. By using current 16 kbit/s Abis links, it ispossible to support CS-1 and CS-2.

In the acknowledged mode of operation, RLC data blocks are acknowledged, CS-1 and CS-2 are supported. Each TBF can use either fixed coding scheme (CS-1 orCS-2), or link adaptation. Link adaptation algorithm is based on RLC BLER(Block Error Rate). Retransmitted RLC data blocks must be sent with the samecoding as was used initially.

In Unacknowledged RLC mode only CS-1 coding is used.


4.9 GPRS radio network parameters and parametermanagement

The Nokia GPRS solution introduces dynamic parameters to help the operator tooptimise the network usage.

For more information, see BSS Radio Network Parameter Dictionary.




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4.10 Frame Relay and Gb Interface

Gb is the interface between a BSC and a SGSN. It is implemented using FrameRelay. Frame Relay can be either point-to-point (PCU-SGSN) or there can be aframe relay network located between the BSC and SGSN. The protocol stackcomprises BSSGB, NS and L1. Frame Relay as stated in standards will be part ofthe Network Service (NS) layer. On top of the physical layer in the Gb-interfacethe direct point-to-point Frame Relay connections or intermediate Frame Relaynetwork can be used. The physical layer is implemented as one or several PCM-E1 lines with G.703 interface. The FR network is comprised of third-party off-the-shelf products

In the first solution (1) spare capacity of Ater and A interfaces is used for the Gb.The Gb timeslots are transparently through connected in the TCSM and in theMSC. If free capacity exists, it is best to multiplex all Gb- traffic to the samephysical link to achieve possible transmission savings. In many cases the SGSNwill be located in the MSC site and thus this multiplexing has to take place thereas well. Normal cross-connect equipment like for example Nokia DN2 can beused for that purpose.

The second solution (2) represent whatever transmission network provides apoint-to-point connection between the BSC and the SGSN. In the third solution(3) Frame Relay network is used. The Gb interface allows the exchange ofsignalling information and user data. Gb interface allows many users to bemultiplexed over the same physical resources.

At least one timeslot of 64 kbps is needed for each activated PCU bearer. A PCUcan connect to 128 TRX/64 cells maximum. This capacity cannot be shared withother cells connected to other PCUs in the BSC so there is no pooling. The PCUhas to be installed into every BCSU for redundancy reasons, but the FR bearerhas to be connected only to the active ones. For example, it is possible to start forexample with two active PCUs to serve all the cells in the one 256 TRX, 128 cellsBSC2E/A. Considering the transmission protection it also needs to be decidedwhether two Frame Relay bearers are needed for each PCU using different ETs(external 2Ms), or if the transmission is protected with cross connectionequipment.

It is possible to multiplex more than one Gb interface directly to the SGSN, ormultiplex them on the A interface towards the MSC and from there crossconnectthem to the SGSN. The 2M carrying the Gb timeslots can be one of the BSC'sexisting ETs or an ET can be dedicated to the Gb interface.

The Gb interface allows the exchange of signalling information and user data. Italso allows many users to be multiplexed over the same physical resources.




In the BSC, each PCU represents one Network Service Entity with own Identifier(NSEI). Each PCU can have one to four (ffs) FR bearer channels. The AccessRate of a FR Bearer Channel can be configured in 64kbit steps. Each Bearerchannel carries one to four Network Service Virtual Connections (NS-VC). EachBTS has a BSSGP Virtual Connection of its own. The NSE takes care of themultiplexing of BSSGP Virtual Connections into the NS Virtual Connections andload sharing between the different NS Virtual Connections (= Bearer Channels).


4.11 Packet Control Unit (PCU) hardware in BSC

The PCU is a unit that controls the (E)GPRS radio resources, receives andtransmits TRAU frames to the BTSs and Frame Relay packets to the SGSN .

Nokia PCU solution has high capacity and reliability. The high capacity isprovided through state of art PCU design and with a future extension possibility.The high reliability is achieved by N+1 redundant PCU units.

The operator can share the BTSs for multiple PCUs, that is, the packet switchedtraffic load can be shared among BCSUs. The operator needs to reserve Gbinterface capacity from all the PCUs, which are connected to BTSs, that is, fromthe active PCUs.

One functional PCU enity can manage up to 256 Abis 16k-sub timeslots, whichare directly mapped to Air interface PDCH channels. Please notice that in BSC3ione PCU plug-in unit includes two functional PCU entities. PCU removes theunnecessary TRAUoverheads coming from the Abis interface and assembles thedata into FrameRelay for the Gb interface. BSC and SGSN are connected to eachother with one or more n*64kbit/s Gb interfaces. The number of interfaces isequal to the number of PCUs, that is, each funtional PCU has its own logical Gbinterface. Gb is a Frame Relay interface and it can be configured in 64kbit/s stepsfrom 1 timeslot up to 31timeslots depending on the capacity requirements.

The design target is that GPRS PCUs can be used with EGPRS. Additionally,there is a possibility to add 2nd PCUs per each BCSU units, 8+1 to increase thepacket switched capacity in second generation BSC products. This 2nd PCUrequires also GSWB extension from 192 to 256 PCMs in BSC2 and BSC2iproducts. Furthermore, the BSCs external connectivity and PCMs can beextended from 112 to 144 external PCMs in BSC2s with 2*ET5C extracartridges.




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4.12 Enhanced Data Rates for Global Evolution, EDGE

Enhanced Data Rates for Global Evolution (EDGE) enhances the data capabilitiesof GSM networks towards 3rd generation services. EDGE increases the Airinterface data throughput in average three-fold compared to today's GSM andboosts both circuit switched and packet switched services. Additionally, EDGE isthe 3rd Generation radio technology for the TDMA/EDGE operators thusconverges the radio networks of GSM/EDGE and TDMA/EDGE.

The Nokia BSS10.5 ED EDGE Solution includes EGPRS for the packet switcheddata and the ECSD. EGPRS uses nine modulation and coding schemes (MCS)which vary from 8.8 kbps up to 59.2 kbps with one timeslot in the radio interfacewith all eight time slots in the radio interface up to 473 kbps.

In EGPRS, the maximum standardised data rate per time slot triples.

The Nokia EDGE solution is implemented on top of the existing GSM networkand requires only minimal hardware and software upgrades to support the airinterface modulation and the increased data rates. EDGE transceivers are able tosupport today's mobile terminals with GSM modulation as well as enhanced dataservices on a time slot basis.

Due to air interface modulation and a lot higher data rates, transceiver units in thebase station need to be changed to make it EDGE capable. These base stationsalso simultaneously support current GMSK modulation, since the modulationchoice can be done per timeslot basis. Also, new mobile terminals are required.However, as an add-on functionality in GSM network, EDGE does not entail anynew network elements.

Benefits of EDGE:

. Migration to wireless multimedia services :

The operator can increase data revenues by offering completely new typeof attractive services to end-users

. Improved end user satisfaction:

Increased data capacity and higher data throughput decrease responsetimes for all data services, thus keeping the end users satisfied andconnected.

. Potentially lower price per bit:

Lower cost of data capacity for high-speed data applications gives theoperator flexibility in pricing.




. Fast network implementation

EDGE does not require new network elements and EDGE capability canbe introduced incrementally to the network

. Optimised network investment as GSM enhancement

Flexible data capacity deployment where the demand is.

Figure 11. EDGE builds on the existing GSM network

The idea behind increasing the data rates is the introduction of 8-PSK (PhaseShift Keying), a linear higher order modulation in addition to the existing GMSK(Gaussian Minimum Shift Keying). An 8-PSK signal is able to carry three bits permodulated symbol over the radio path, while a GMSK signal carries only one bitper symbol. The carrier symbol rate (270.833 ksps) of standard GSM is kept thesame for 8-PSK, and the burst length is identical to the current GMSK using thesame 200 kHz carrier spacing.

EGPRS MCS-1...MCS-9

MSC

Gn

GGSN

GbA

BTS

OSS

EDGE capableterminal,GSM compatible

GSM/EDGE coverage

BTS

Nokia UltraSite EDGEBTS Nokia MetroSiteEDGE BTS GSMcompatible

A-bis

EDGE functionality innetwork elements

8.6.0-

0

More capacity ininterfaces to supporthigher data usage

and higher user rates



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Table 4. Peak data rates for single slot EGPRS

MCS Modulation Code rate Family User rate

1 GMSK .53 C 8.8 kbps

2 GMSK .66 B 11.2 kbps

3 GMSK .80 A 14.8 kbps

4 GMSK 1 C 17.6 kbps

5 8PSK .37 B 22.4 kbps

6 8PSK .49 A 29.6 kbps

7 8PSK .76 B 44.8 kbps

8 8PSK .92 A 54.4 kbps

9 8PSK 1 A 59.2 kbps

GMSK modulation provides the robust mode for wide area coverage while 8-PSK provides higher data rates. The MCSs are organised in families in order toallow re-segmentation of the data block for link adaptation. The protection thatbest fits the channel condition is chosen for maximum throughput, as higherprotection means lower throughput.

The user can send more data per radio time slot with the same amount of air timeused and operators do not need to invest in another frequency band and license tooffer higher data rate services like mobile multimedia.

Due to new air interface modulation and a lot higher data rates, transceiver unitsin the base station need to be changed to make it EDGE capable. These basestations also simultaneously support current GMSK modulation since themodulation choice can be done per time slot basis. Also, new mobile terminalsare required. However, as an add-on functionality in GSM network, EDGE doesnot entail any new network elements.





4.13 Nokia Smart Radio Concept for EDGE (Nokia SRC)

Nokia Smart Radio Concept (SRC) is an important feature for getting themaximum EDGE benefit, first phase supported by Nokia UltraSite EDGE BaseStation with BSS10 hardware and software.

SRC is a feature that enhances the radio performance of the BTS, both in EDGEand GSM mode. The Nokia SRC includes a combination of diversity solutionsapplied in both uplink and downlink directions. The Nokia SRC for EDGE isused to improve radio link performance to ensure maximum coverage, improveddata capacity and high service quality. For utilising the Nokia SRC, EDGEcapable equipment is required.

Intelligent Downlink Diversity, IDD

The antenna diversity gain is also applied in downlink enhancement, through afeature called Intelligent Downlink Diversity (IDD). In IDD the cell coveragearea is extended by sending simultaneously the same downlink signal throughminimum of two transmitters, with slight delay. Two antennas (or X-polarisedantenna) are needed for one cell.

The IDD boosts downlink performance by up to 5 dB (min. 3 dB), in all radiotimeslots. The typical configurations in one UltraSite EDGE Base Station cabinetare, for example: 1+1+1 with combiner by-pass, 2+2+2 with 4-way diversity and6 TRXs/cell with RTC for large coverage and high capacity needs. In every caseadditional TRX for diversity transmitting is required.

Transmission takes place through two TRXs and antennas. Auxiliarytransmission is delayed 1-1.5 symbol periods, which gives good performance forall modulation schemes. Random Phase hopping degreases correlation betweenthe main and auxiliary transmitter. Correlation between the antennas has to below.

All timeslots are transmitted through two transceivers and antennas, all radiotimeslots are sending in BCCH carrier.

4�way uplink diversity and Interference Rejection Combining, IRC

The uplink performance (BTS reception) is enhanced with the combination ofInterference Rejection Combining via 4-way diversity reception of the BTS andsensitivity optimised high-gain Nokia UltraSite Masthead Amplifiers (UltraSiteMHA introduced already in BSS9).

IRC tries to null correlated noise received by both antennas.



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If there is no correlated noise (interference), then IRC behaves like normalMaximum Ratio Combining.

Gain of IRC depends on Dominant Interference Ratio and angular spread ofinterference [PAR].

Post Detection Maximum Ratio Combining is then used for two IRC combinedsignals providing up to 3dB ideal method for dual X-polarised antenna conceptproviding capacity and coverage enhancements.

IRC utilises auxiliary transceiver effectively for both the UL and DL.


4.14 Support of PCCCH/PBCCH

This feature brings dedicated CCCH capacity for (E)GPRS services.

PCCCH comprises logical channels for packet common control signalling. Thefollowing common control channels are available:

PRACH is used by MS to initiate uplink transfer for sending data or signallinginformation. Packet Access burst and Extended Packet Access burst are used onPRACH.

PPCH is used to page an MS prior to downlink packet transfer. PPCH usespaging groups in order to allow usage of DRX mode. PPCH can be used forpaging of both circuit switched and packet data services. The paging for circuitswitched services on PPCH is applicable for class A and B GPRS MSs inNetwork operation mode I.

PAGCH is used in the packet transfer establishment phase to send resourceassignment to an MS prior to packet transfer.

PBCCH broadcasts packet data specific System Information (for example C31and C32 cell selection criteria). C31/C32 are used to direct the GPRS traffic onthe cells, which can serve EGPRS most efficiently and interference free to CStraffic. C31/C32 apply in cells using PBCCH/PCCCH, otherwise existing C1/C2are used.

If PBCCH is not allocated, the packet data specific system information isbroadcast on BCCH.

Note




PCCCH/PBCCH are mapped to own timeslot. It should be configured on thesame TRX as BCCH in the case of Multi-band cell.

Figure 12. Support of PCCCH/PBCCH

Back to Overview to GSM/EDGE Feature Description. .

4.15 Priority Class based Quality of Service

At a system level the concept of 'Priority Class' is introduced. This is based oncombinations of GPRS Delay class and GPRS Precedence class values. Packetsare evenly scattered within (E)GPRS territory between different timeslots. Afterthat packets having higher priority are sent before the ones having lower priority.

Currently all TBFs (GPRS calls) have same priority. All users and all applicationsreceive the same service level. The needs from different applications differ andmechanisms to have separate service levels are required. ETSI specificationsdefine QoS functionality, which gives a possibility to differentiate TBFs by delay,throughput and priority. Priority Based Scheduling is introduced as a first steptowards QoS. With Priority Based Scheduling operator can give users differentpriorities. Higher priority users get better service than lower priority users. Thereis no extra blocking to any user, only the experienced service quality changes.

The scheduling algorithm gives each link a so-called latest service time, beforewhich the connection should get a chance to use the radio resource. After the linkhas used the radio resource it is given a new latest service time, which is thecurrent time plus a predefined step. The connection that has the smallest latest

Common Channels

BCCH/CCCH PBCCH/PCCCH

PBCCH PPCH PDTCH PAGCH PRACH



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service time gets to use the radio resource. Periodically the scheduling algorithmcomes and checks on the queue. In Nokia GPRS release 1 these steps are set tothe same constant value for all TBFs. This in effect produces a round robin likequeuing system.

The algorithm is priority based. It selects the best possible time slot withinterritory and then prioritises the TBFs residing in that timeslot so that the TBFwith the highest priority gets the most air interface. As the solution does not affectthe allocation process the number of customers served stays constant whencompared to Nokia GPRS release 1.

Each timeslot has a queue in which the TBFs wait for their turn to use the radioair interface. After the TBF has used its air interface time it increases it's latestservice time to the current time plus it's scheduling step size. The use of thecurrent time is explained by new TBFs coming in to the system, all TBFs muststart from the same situation.

The algorithm has a direct impact on the scheduling algorithm. The sizes of thescheduling steps have to be set so that they reflect the handing out of radioresources, because the time a certain link has control of the radio resource isdecided by the scheduling algorithm. Each service class is given fair amounts ofradio time. The only exception being best effort customers, who are given a smallshare of the radio interface. Priorities are implemented by giving differentscheduling step sizes for different QoS classes. Scheduling step sizes are operatoradjustable. There are 4 QoS classes for uplink, and 3 QoS classes for downlink.

This algorithm provides priorities between TBFs in the same timeslot so that theTBFs that have the same QoS get an equal share of airtime. However equal airtime does not provide equal data rates for the TBFs in the same time slot, it onlyguarantees that inside a QoS group the air time is divided equally and that ahigher QoS class gets more air time.

Mobile specific flow control is part of the QoS solution in the PCU. This featureworks together with the SGSN to provide a steady data flow to the MS from thenetwork. It also is an effective countermeasure against buffer overflows in thePCU.

Priority Based Scheduling in BSC is standard feature and subscriber priorityneeds to be defined in HLR once this feature is taken into use.





4.16 System Level Trace

This system level feature extends the tracing facility to the GPRS service.Currently tracing is available in the network elements of the GSM network totrace circuit switched calls.

The trace facility enables customer administration and network management totrace activities of various entities (IMSI s and IMEI s), which result in eventsoccurring in the PLMN . Trace facility is a useful maintenance aid anddevelopment tool, which can be used during system testing. In particular, it maybe used in conjunction with test-MSs to ascertain the digital cell 'footprint', thenetwork integrity and also the network quality of service, as perceived by thePLMN. The ETSI specifies the Trace facility for GSM, where it refers to:

. Subscriber tracing (tracing of IMSI)

. Equipment tracing (tracing of IMEI)

Figure 13. Trace activation/deactivation and report generation

The subscriber tracing can be defined for a certain subscriber in the HLR or in aspecific SGSN. Equipment tracing is can be defined in the SGSN.

Trace is already implemented in GSM network, but introduction of GPRS serviceadds new network elements to GSM network (GGSN, SGSN) and changes oldprinciples: existing trace features are updated.

Active/deactive trace(Subs. or Equip.)

OSS

GSMNetwork

GPRSnetwork



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The network management can use the facility for subscriber trace, for example, inconnection with a customer complaint or if equipment malfunction is suspected.

The trace facility enables the network management to trace the activities of IMSIsor IMEIs that result in events within the PLMN.

In SGSN trace three different scenarios can be identified from operators'viewpoint:

. HPLMN operator traces its own IMSI within the HPLMN

. HPLMN operator wants to trace foreign roaming subscriber (IMSI) withinits own HPLMN

. HPLMN operator wants to trace equipment (IMEI)

When an operator wishes to trace GPRS subscriber in own (home) network, traceis first activated in HLR. If subscriber is not roaming outside HPLMN and he/sheis registered in HLR, the HLR activates trace in specified SGSN. Otherwise HLRwaits until the subscriber becomes active in HPLMN before it activates trace inSGSN.

When an operator wants to trace a foreign subscriber, trace is activated directlyvia MMI commands to all SGNSs in operator's network. Trace of subscriber is instate active pending, until an invoking event occurs. Amount of active trace casescan be limited.

When an operator wants to trace equipment, trace is activated directly via MMIcommands to all SGNSs in operator's network. Trace of equipment is in stateactive pending, until an invoking event occurs. Amount of active trace cases canbe limited.

The tracing of roaming IMSIs and the exchange of data is subject to bilateralagreements and the request to trace a particular IMSI comes throughadministrative channels. The HPLMN operator can use the HLR parameters todefine whether the trace settings are sent to the VPLMN.

NEs involved

Trace is a system level feature and in order to get full advantage of trace it mustbe implemented in all main network elements of GPRS network: SGSN, GGSN,BSC, MSC/HLR and Nokia NetAct.





5 Operability

The features and functionalities presented in the following sections are related tothe operability of the Nokia BSS.


5.1 Rx antenna supervision by comparing RSSI value

The purpose of this feature is to monitor the Rx antenna condition. Rx antennascan be monitored for major problems by taking a long-term average of thedifference between main Rx RSSI and div Rx RSSI (Received Signal StrengthIndication). This feature provides continuous antenna supervision for the BTSs,which have main and diversity antennas in use. It also offers an alternativesolution for Tx monitoring in cells that use duplexing. For example, this detectsantennas with poor VSWR and inadequate feeders.

The monitoring is based on the principle that all received bursts where the Rxlevel of main or diversity branch is above the defined limit value (-95dBm) areaccepted as samples and used in the averaging process. The differences of theTRXs connected to the same antennas are counted up and the average differenceper main and diversity antennas is calculated. If the difference is above thethreshold (default value 10 dB), an alarm is activated. For the Nokia PrimeSiteBTS, the Rx branch difference is calculated separately per TRX. The thresholddefault value of 10 dB can be changed by a parameter at the BSC between 5-64.The functionality of the feature can be disabled by using the maximum value.

It is still possible that both antennas are damaged simultaneously and thedifference algorithm cannot detect the fault. For this reason, the BTS alsoobserves the assignment and handover success rate per antenna. Excessivefailures trigger the antenna test, and if necessary, an SWR alarm is raised.




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5.2 TRX monitoring by RSSI

Rx Antenna Supervision by Comparing RSSI Value is enhanced so that theO&M unit of the BTS compares RSSI values from different TRXs connected tosame antennas. If some of the TRXs have lower signal level than the averagevalue, a non-blocking alarm is sent to the BSC indicating a faulty TRX.

This method brings a possibility to supervise TRXs also when they are used in aBB hopping cell.


5.3 Redundant BTS station unit

As the operation of the common units of a BTS site is critical for the operation ofthe whole BTS and service, the maximum reliability must be ensured.

Some of the units common for the whole site can be duplicated for the maximumreliability. The unit redundancy is available for the Master Clock unit (MCLx) ,Frequency Hopping unit (FQHU) and for the Station Unit Power Supply (SUPx) .Any combination of these redundancy options is allowed, combinations are notdependent on each other in any way.

Note

If diversity is used, the second FQHU is not used for redundancy, instead it isrequired for the diversity receiver signal path.


5.4 Double BCCH allocation list

This feature introduces the possibility to define a list of BCCH carriers to be usedin cell selection and reselection by the MS, which is in idle state.




The list is sent to the MS in System Information Message type 2 on the BCCH ,and the MS may store it when powering down. Now the MS does not have tosearch through the whole band when powering up. If the list contains all theBCCH carriers of a certain geographical area of a PLMN, the MS can use it tosearch the suitable RF channels quickly in order to camp on a cell.

Another aspect of this feature is that the operator is able to monitor all theneighbours of a certain cell. By using the idle state BCCH allocation list, whichcontains all BCCH frequencies (which is different from active state list) during acall, it is possible to get information about the neighbours which are not definedin the active state neighbour list (and are thus missing from the adjacent celldefinitions even though they may be good adjacent cell candidates).

When the lists are created the operator may assign cell by cell any of those BAlists to BCCH allocation idle state list and the same list may also be assigned tothe BCCH allocation neighbour cell list. If the operator does not assign a BA listto the BCCH allocation idle state list the list of real neighbours - specified in theradio network database - is used as default.

For more information, see Double BCCH Allocation List .


5.5 Undefined adjacent cell measurements

The undefined adjacent cell measurement collects statistics about cells which arenot defined as adjacent cells to a cell, but are among the six neighbouring cellsthe MSs receive best.

Statistics are compiled in counters reserved for each BSS cell. The measurementis able to maintain information on up to 32 undefined adjacent cells per each BSScell.

Note

This feature requires the feature Double BCCH Allocation List, which providesservices to specify a list of the measured BCCH frequencies.

For more information, see Double BCCH Allocation List .




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5.6 Flow control

This feature reduces the traffic in congested signalling cases.

When the BSC receives an overload message from the MSC, traffic is reduced byone step. This step reduction involves barring of one mobile access class, whichis performed by sending a new system information message via the Abis Interfaceto the MSs. Timers T17 and T18 are started. Overload messages incoming fromthe MSC are ignored until the T17 expires.

The reception of an overload message after the expiry of the T17, T18 still beingset further, reduces the traffic by one step. The timers T17 and T18 are bothrestarted. This reduction of traffic is continued as long as there are incomingoverload messages, and steps to reduce traffic.

The same step-by-step mechanism is also used to increase traffic, if no overloadmessages are received during T18.

The step-by-step method described above is used in a congested signallingsystem.

Message overflow at BTS

The BSC receives messages from the BTS on a regular basis. The messagesindicate the load situation in paging and random access channels. Paging messageoverload is transferred to the MSC in order to reduce paging in this particular cell.Because the BSC does not have the means to reduce the paging traffic in anysophisticated way, the BTS handles the discarding of the paging commands that itcannot send.

An access grant channel message overflow is indicated by the reception of adelete indication message from the BTS. In this case the BSC skips sending thenext reject message to an MS, but sends all immediate assignment messages. Thisguarantees the maximum use of allocated radio resources.

LAPD overload

LAPD overload occurs only in the uplink direction, because radio measurementreports are transferred from the BTS (and MS) to the BSC. The control of thisoverload is a matter of network configuration and the BTS.

Internal processor overload control

Centralised unit overload




The main loading sources are the random accesses coming from the MSs throughrandom access channels. In addition, there are handover requests. Both of theseare handled by the radio resource management. In order to maintain service forestablished connections, random accesses are addressed with low priority to theradio resource management; handover requests and TCH requests are addressedwith higher priority to the radio resource management.

In high load situations, therefore, fewer new call attempts than usual are handledand fewer new connections established. Handover requests, however, receivefaster service.

Distributed unit overload

Most of the messages received are radio measurement reports coming from theBTS and the MS. These messages come from the LAPD link. Before messagedistribution, the processor load state is checked. If the load exceeds a certainpredefined limit, the message is discarded. The message buffer and processingcapacity demand is thus decreased.

The loss of the radio measurement report does not affect the service qualitysignificantly; some reports are lost anyway owing to the load on the LAPD link.The method of discarding messages is random as well, so the loss of messages forone particular connection stays within reasonable limits.

For more information, see Flow and Overload Control .


5.7 BSC hardware configuration management

With the functions of the BSC hardware configuration the capacity of a BSC canbe increased or new features can be taken into service in a controlled mannerduring its operation.

New units can be installed into existing hardware without the risk of functionaldisturbances in the traffic-transmitting part of the BSC. Here the possibilitiesoffered by hardware redundancy can be made use of by installing the hardware ofthe new unit first to that half of the control part that is separated by means ofsoftware management.

The hardware configuration management provides the services for the operatorthrough the MML interface. The management includes creating and deletingracks, cartridges, functional units and plug-in units. The configuration data of theunits can be defined and displayed.



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Wired alarm inputs can be opened and closed, and the open alarm inputs can belisted.

For more information, see Hardware Configuration Management.


5.8 BSC MML authorisation

The Man-Machine Interface (MMI) authorisation system is used for the operatoraccess control both in local Man-Machine Language (MML) sessions and inremote sessions.

The function of the operator access control, the authorisation system, is to ensurethe access for authorised users only and to prevent the users from executingunauthorised commands. In other words, it has the following goals:

. to allow the operator an access only to that part of the system on which he/she has expert knowledge

. to give the operator a permission to use only that part of the system whichhe/she is required to use

. to prevent input of commands associated with certain parts of the systemfrom certain display terminals

Every MML session and MML command passes the authorisation check, whichis done on three different aspects. All these must be fulfilled to allow theexecution of a command:

. user password defining the user's privilege level

. the rights of the terminal

. authorisation demand of the command

In order to prevent unauthorised use of the MMI functions, the MMI systemclassifies the session after getting the user's password at the beginning of theMMI session. The session class is defined on the basis of the given password andthe rights of the terminal, which is used in the session.

The MML commands are divided into authorisation groups based on the objectsof the commands and on how harmful effects they may have on the system ifused improperly. The user is allowed to execute only those commands where thedemanded authority group is in accordance with the session class.




The following means are provided for the management of the operator accessescontrol:

. defining the user profile, which includes the user identification, thepassword and the user privilege level

. modifying and deleting a user profile

. interrogating user profiles

. listing the users who are currently logged in the system

. listing MML commands in a given authority level

. interrogating and modifying terminal rights

. setting validity period for user's password


5.9 BSC software configuration management

By means of the BSC software configuration management the operator candeploy a new software package in the BSC, update an existing package, test newsoftware before its deployment, and safe-copy the software of the BSC. Thesefunctions make it possible to load, test and deploy new software, or a specifiedpart of it, under controlled conditions in the BSC.

The BSC can maintain several software packages on its system disk at the sametime. A sufficient maximum configuration for everyday needs is three packages.Various packages may contain common software components. The master files ofdifferent packages may thus contain common records. It is therefore possible tomake use of the old package simply by introducing only those softwarecomponents that have changed. It is also possible to make a safe-copy of thepackage in operation, to compare two software packages of different levels and toexamine the change history of the packages. Safe copying can be made for thewhole package or for the data files only.

The most significant software change means that all the software components of apackage are changed, and the least significant that only one component ischanged. Software configuration management supports all software change cases.Conversion programs serve to retain the semipermanent data (file contents), eventhough its format may change in the new package. Significant software changescan be employed safely through a trial configuration.



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Trial configuration is a functional division of the BSC into two parts,accomplished with package management commands, in which there is a traffic-transmitting part (traffic side) and a software-testing part (trial side). The parts areinvisible to each other and can have different software packages. The traffic sidehandles the traffic with old software, while the new package can be tested on thetrial side without disturbing traffic.

Automatic return to old package

It is required that a BSC software package can be changed and activated remotelyfrom Nokia NetAct. This feature enhances the functionality of the remote BSCsoftware updating.

To ensure that the BSC and its remote connections start working correctly afterthe package deployment, this feature provides automatic return to the previouspackage if the remote connection fails or if other severe malfunction occurs in theBSC's Operation and Maintenance Unit preventing the operator from remoteoperations.

Two different return conditions can be given to the BSC:

. return to back-up package allowed

. return to fallback package allowed

Two modes of automatic return can be used:

. immediate return in case of the Operation and Maintenance Unit does notstart up

. timed return to the old package if the remote connection does not begin towork

With the enhancement 'Installing Multiple Change Deliveries' it is possible toinstall more than one CD before creating a correction package. It is particularlyuseful when making a BSC software upgrade or when commissioning a BSC forthe first time, as in these cases we usually have to install many CDs at the sametime.

The enhancement Improved Local Back-up introduces a one-command safecopy.The back-up application takes care of the whole procedure: the preparatoryactions, copying and the finishing actions. Command calendar files for remotesafecopying is no longer needed. Another enhancement is that an archive back-upcan also be taken after change deliveries have been installed.

For more information, see Software Configuration Management.





5.10 BTS hardware database management

The BTS hardware database contains an accurate description of the equipmentconfiguration of the BTS site. The database is stored in the non-volatile memoryof the Base Control Function (BCF) unit of a BTS site.

The BTS hardware database management makes it possible to manage all theBTS hardware databases without a need to visit the BTS site. Databases aremanaged and stored at the BSC and they are loaded down to the BCF whennecessary. The system also enables the operator to upload the database from theBCF to the BSC if local modifications at the BTS site have been made.

Database file downloading is executed when the BCF is restarted if there is nodatabase in the BCF's non-volatile memory. Downloading can also be done as abackground operation when the hardware database is activated.

A new BTS hardware database is transferred into the BSC on a floppy disk orthrough the operation and maintenance network by means of the FTAM (FileTransfer, Access and Management) protocol. Database modifications are madewith a PC equipped with a BTS-MMI program. It is possible to edit a hardwaredatabase located in the BSC's disk by connecting the PC to a service terminal portof the BSC. The modified databases are stored at the BSC for back-up and theycan be loaded down to the BCF.

BTS hardware database management functions can be used by MML commandsat the BSC. The operator can create and delete a hardware database, attach adatabase to a BCF and detach a database. With an activation command theoperator can activate a certain hardware database on a BCF. The operator can alsoreplace a certain database with another database or erase the contents of the non-volatile memory of a BCF.

With output commands the operator can list information of the hardwaredatabases created in the BSC and the hardware database configuration of BCFs.

For more information, see BCF Hardware Database Handling.




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5.11 BTS local user interface - BTS MMI

Local access and control over the BTS are required especially duringcommissioning and later during service and maintenance activities.

The BTS-MMI is a menu-based software, which allows users to monitor andcontrol the operation of the BTS and to configure it during commissioning. TheBTS-MMI can be used even if there is no Abis-connection available to the BSC,and thus making it an ideal tool for commissioning and testing.

The local access to the BTS via the BTS-MMI can be password protected. Thepassword is saved to the non-volatile memory of the BCF unit of the BTS and itcan be changed only locally on sites with the BTS-MMI. If the password ischanged, an alarm is generated to the BSC to indicate this. It is also possible toomit the password inquiry if there is no need for it.

The BTS MMI offers an unrestricted access to the BTS tests and units. All testfacilities are available from the BTS MMI including RFTE /STM loops, STMtests (such as antenna loops, sensitivity, test calls) and BBU tests. The devicecontrol functions can be used in the BTS testing, for example, the transmitter canbe switched on at the desired power level and frequency, if necessary. Operatingsoftware can be locally loaded via a connection to the BCF unit of the BTS.

TRXs or the whole site can be reset with a BTS MMI command. Objects can alsobe locally blocked from operation for local maintenance purposes. If an objectneeds to be taken away from service, a local block command from MMIgenerates a blocking alarm to BSC, which blocks the object from service. TheBSC then clears all calls from the concerned TRX and takes appropriate measuresto restore traffic on remaining TRXs as it would do with real equipment failure.Object can be restored back to traffic with unblock command.

All active alarms of the BTS can be listed with BTS MMI. Listing contains eitherall alarms (the unit level view) or relevant alarms, where some alarms are filteredaway based on the configuration.

The Menu Based HW Database Editor assists users in creation of the HWdatabase. It has built-in knowledge of the possible configurations available withdifferent cabinet types. When defining the contents of the database, the user hasto input only some general level information, such as cabinet type, number ofsectors, number of TRXs and also number of some other units. Based on this andon the built-in information about the different configurations, the tool canautomatically generate a HW database.




The tool has different levels of details available according to the user needs. Thetop level contains more or less the parameters described above, the other levelsprovide increasing number of details and control over the other parameters in thedatabase.

Note

The BTS MMIs for Nokia 2nd generation, Nokia Talk and Nokia PrimeSite BTSfamilies are different applications. Above description is generic and it applies toboth applications.


5.12 BTS software package management

Easy commissioning of BTS as well as fast and secure software upgradingrequire remote management for BTS software packages without a need to visitthe BTS site. Back-up copies, background downloading and storage for severaldifferent packages are essential.

With the BTS software package management the operator is able to store 40different BTS software packages in the BSC. Any of the packages can be attachedto any of the BTS sites and then they can be loaded down to the Base ControlFunction (BCF) units of the BTS sites.

All BTS software package management functions can be done by using MMLcommands at the BSC site, or remotely through Q3 from Nokia NetAct. A newBTS software package can be transferred into the BSC on a floppy disk orthrough the operation and maintenance network by means of the FTAM (FileTransfer, Access and Management) protocol.

BTS packages are stored on the BSC disks. The operator can create and delete asoftware package, attach a package to a BCF, detach a package and define aninitial SW package in advance for each BTS generation. The operator can restarta BCF with a certain software package and change the status of the packages.There are also output commands that list information of the packages created inthe BSC, list the contents of the package, and list the software configuration ofthe BCFs. Ongoing package management operations can also be listed. Softwaredownloading is executed on BCF restart when it does not have a softwarepackage to activate. Downloading can also be done as a background operationwhen a BTS package is being attached to the BCF.



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The BTS is also capable of storing SW packages locally. This further reducesservice interruptions during site resets. After a SW package has been downloadedto the BTS either via BCF reset or via online loading, it can be saved to non-volatile FLASH-memory of BTS O&M unit. Then, during the start-up procedure,BSC and BTS compare the master file identities and if they match, the SWpackage is loaded from FLASH instead of transferring the package from BSC'sdisk. Depending on the size of the FLASH memory, one or two SW packages canbe stored locally at site.

For Nokia Talk-family and Nokia PrimeSite BTSs also the firmware can beremotely upgraded except for the transmission unit TRUA. Firmware file packetsare stored as a part of the BTS software package and are not as such visible to theuser nor require any special actions. This eases a possible field upgrade as it is notnecessary to visit the site physically. The feature includes improvement DefaultBTS SW Package per BTS Generation.

For Nokia UltraSite BTSs, software downloading is executed after BCF reset ifthe BOI does not have correct software. The BTS software can also bebackground downloaded to the BOI when a BTS software package is beingdeployed to the BCF.

Downloaded BTS software application files are stored in the BOI non-volatilememory. The files are also copied to the BB2x. Local BTS software backupminimises BTS boot-up time because there is no need to download the BTSsoftware package from the BSC after each reset.

For more information, see BCF Software Handling.

Back to Overview to Overview to GSM/EDGE Feature Description.

5.13 Command calendar

Some routine maintenance tasks may need to be executed regularly, or forexample, at night. Daily routines can be programmed to be run by the commandcalendar. The command calendar allows executing long MML command setseasily beyond the regular working hours.

An MML command or a command file can be set to execution at a requestedtime, once, or continuously by means of the command calendar. In addition to thetime, it is also possible to start the execution of the command file by detection ofa particular alarm.




The management of command files in the command calendar makes it easy toalter the command files. Commands can be added to or deleted from theexecution queue of the calendar. The commands set to the calendar can be printedout. The state of the command or command string in the calendar can bemodified, the execution is either allowed or prohibited. It is possible to test thesemantics and the execution of a command or command string from the calendarbeforehand.


5.14 Command file

The command file allows executing long MML command sets easily. Acommand file is a file stored on the system disk containing MML commands withtheir parameters. The command file can be set for execution immediately or at arequested time by means of the command calendar.

The command file can be created with an external editor or with the disk fileeditor of the DX200 system. The command log file made by the MMI systemabout each session can be taken as the basis for the editing.

The operator can set the command file for execution, interrupt its execution andprint the contents of the file out. The command log file can be printed out, and itscontents can be modified to form a new command file.


5.15 External Battery Back Up unit support

The External Battery Back Up (BBU) unit can be handled in the same way as theinternal BBU unit in the Outdoor All Climate cabinets. This comprises of threealarms from the BBU and one control line to the BBU. Control line support isneeded for switching the rectifier off and on during a battery test. Up to threeunits of external BBUs are supported.

This feature is activated by setting the required definitions to the BTS hardwaredatabase.

Note

BBU alarms are not sent to the BSC during a BBU test.



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5.16 Forced handover for O&M reason

The aim in all operating tasks should be avoiding any disturbance to traffic. Whenan O&M operation requires blocking of an active cell or the working TRX, theongoing calls can be handed over to the other TRXs of the cell or to neighbouringcells by means of the forced handover procedure.

Forced handover is available with the commands 'Lock BTS' and 'Lock TRX' asan option. The operator is able to determine the maximum time, during whichhandovers are attempted to make. Also the features Intelligent Shutdown withTimer Control and Preferred BCCH utilise forced handover.

With the forced handover procedure all ongoing calls are attempted to hand overto other TRXs of the cell (if only one TRX is cleared from the traffic), or to theneighbouring cells (if the whole cell is cleared). During the execution of theforced handover procedure, access to the cell or TRX is barred to prevent MSsfrom new call attempts. Incoming handovers to that particular cell or TRX arealso prevented.



5.17 Frequency plan changing

A major part of a frequency plan may require changing when new cells orchannels are introduced to the network. Occasionally the entire plan is changed.

In an operation network, large changes are critical in regard to the timeconsumption, network consistence and safety. The new plan must be taken intouse overnight without remarkable degrading of the service. If the new frequencyplan is changed from Nokia NetAct in the conventional way, that is, first lockinga TRX, then changing its frequency, and finally unlocking it, the whole operationfor a large network may take too long.

This feature offers an advanced way to make large changes into the frequencyplan. The following essential matters are covered:




. The new plan is loaded down as a background operation without effectingthe actual plan. The plan may come either from Nokia NetAct or from thelocal MML interface.

. Downloading errors are tolerated. Possibly interrupted downloading maybe repeated without harmful effects on traffic performance.

. New plan is quickly activated in the radio network after the downloadingand possible consistency checking. Thus, disturbance in the network isremarkably shorter than previously.

. The previous plan stays in the BSC for back up. It may be reactivatedquickly.

The following network plan parameters are supported by this feature:

. Frequencies

. Frequency Hopping parameters

. Base Station Identity Codes (BSIC) and Training Sequence Codes (TSC)

. TRX parameters of the Intelligent Underlay-Overlay feature


5.18 Intelligent BTS shutdown due to mains break

To provide protection against mains break a BTS site may be equipped withbattery back-up. The aim is to maintain service as long as possible. To achievethis it is reasonable to reduce capacity on certain sites in order to save battery andmaintain only the essential BTS functions.

This feature provides means to control the site equipped with battery back-up incase of mains break. As the power consumption depends on the equipmentsupplied by the back-up batteries, shutting down a part of the site prolongs theremaining service time.

On a BTS site basis, the operator can define the service level of the site to bemaintained while battery back-up is in use. Also the operator can define twotimers to allow executing the shutdown procedure in several phases. Threeservice level options are available:



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1. Full service. Service is maintained on full level as long as batteries last.

2. BCCH back-up. Only BCCH TRX(s) are maintained to offer minimumservice, other TRXs are switched off. Non-BCCH TRXs are switched offafter the first timer expires. Timer two has no meaning in this case.

3. Transmission back-up. Only the BTS transmission equipment power issupplied. TRXs are switched off and BCCH transmission is stopped. Thissecures the functionality of a transmission chain. Non-BCCH TRXs areswitched off after the first timer expires. Then the timer two starts and afterit expires, BCCH TRX is switched off and only transmission equipment isleft powered to maintain transmission links for chain configuration.

When a mains break takes place, the BTS sends an alarm to the BSC, whichperforms forced handovers for all the calls on the TRXs to be shut down. Thecalls are handed over to a TRX, which remains powered, or to adjacent cells. If allthe necessary handovers cannot be made during the defined maximum time thecalls are released. Finally, the BSC orders the BTS site to power down the TRXs.

When the mains power restores the BSC takes the BTS automatically back in fullservice.

Third party BBU equipment can also be used together with intelligent shutdown.It is possible to designate an external alarm line which is used to indicate a mainsbreak to the BTS. This alarm is then sent to the BSC as a mains break down alarmwhich then triggers the shutdown procedure.


5.19 Online BTS software loading

When upgrading the BTS software level it is desirable to minimise the down timeof BTSs.

A new BTS software package can be loaded down to the BTS online duringnormal operation. The downloading takes place as a background operation whilesupervision and alarm functions as well as call control are all active. This meansthat the duration of downloading of a software package is not included in thedown time of the BTS. The same applies also to downloading of a new BTShardware database.

During downloading the new package is saved to the non-volatile memory of theBase Control Function (BCF) unit of a BTS site. When the new software packageis activated, only a site reset is required and the new software is immediatelyavailable on the non-volatile memory.




For more information, see BCF Software Handling.


5.20 Radio network configuration management

To run a mobile network requires managing a number of radio network elementsand parameters controlling the functions of the radio network. As the radionetwork configuration is not static, but changes due to an increasing demand ofcoverage and capacity, fast and easy-to-use access to the configuration data isrequired. In addition, changes must not cause unnecessary service breaks.

The radio network configuration management in the BSC supports managing theradio network structure and data in case of

. building the radio network

. expanding the network

. reconfiguring the network

. changing and optimising the functioning of the network

. deploying advanced features into the network

Most of the changes can be made online. This means that when makingconfiguration or parameter changes concerning, for example, a base station, otherbase stations are not disturbed.

The radio network data consists of logical radio network objects and theirparameters stored in the Radio Network Database of the BSC. The managedobjects are: BSC, Base Control Function (BCF), Base Station (BTS), Transceiver(TRX), Radio Timeslot (RTSL), Handover Control Parameters per cell (HOC),Power Control Parameters per cell (POC), Adjacent Cell definitions (ADJC),Frequency Hopping Systems per cell (FHS), BCCH Allocation Frequency List(BA), Mobile Allocation Frequency List (MA) and Trunk Reservation ThresholdTable (TRK_TBL).

The following operations are supported:



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. Creating and removing objects (BCF, BTS, TRX, ADJC, BA, MA, andTRK_TBL) in the database.

. Changing of parameter values. The change is distributed and activatedimmediately. Changes in the following objects are possible online, they donot cause any break in the service: BSC level parameters, handover andpower control parameters, adjacent cell definitions, BA frequency lists,trunk reservation tables, most of the cell parameters.

. Managing frequency hopping (both baseband hopping and radio frequencyhopping).

. Interrogating parameter values.

. Changing the administrative state (LOCKED/UNLOCKED) of the object(BCF, BTS, TRX, and RTSL).

. Displaying the operational states of the functional entities (BCF, BTS,TRX, and RTSL).

The enhancement 'Three Digit Mobile Network Code' allows the use of 3-digitMobile Network Codes (MNC). The maximum number of networks is 1000within one country within one Mobile Country Code (MCC).

In an enhancement 'Radio Network MML Improvement' there are improvementsfor Output Radio Network Configuration and Check Adjacent Cell Data MMLcommands. There is also a command for checking that the amount of IUOinterfering cell definitions does not exceed the allowed maximum.

The enhancement 'Guard Channel Management' enables the use guarded channelsby controlling the maximum TRX transmit power. The GSM1900 frequencyband in the USA consists of channel numbers 512 to 810. The band has beenfurther divided into six sub-blocks A, B, C, D, E, F, blocks A to C being 15 MHzbands and D to F being 5 MHz bands.

The FCC, the local regulator in the USA, has set certain emission limits forGSM1900 equipment to ensure that an operator on a band does not interfereanother operator on the adjacent bands. The edge channel between two adjacentblocks must not be used at all. Two more channels next to the edge channel maynot be used on the maximum transmit power. The result is that there are threechannels between each two adjacent sub-bands that can not be used freely. Alsothe extreme edges of the GSM1900 band, channels 512 and 810, belong to thelow power category. The BSS has the responsibility to control the edge channelemission limits.

For more information, see Radio Network Configuration Management.





5.21 Radio network fault recovery

Radio network maintenance in the BSC provides facilities for maintaining theradio network operational if a fault occurs in the BSS.

In addition to detection and indication of faults in the BSS, the BSS executesautomatic procedures that minimise the effect on the quality of the service. Thealarm handling system makes decisions on the basis of alarm indications andactivates the radio network recovery when necessary.

In case of a fault at a BTS site the BTS sends an alarm message to the BSC andindicates the accused object and whether it is operationally enabled or disabled.Faults in the Abis transmission path (PCM fault, LAPD signalling link fault) aredetected by the BSC. The possibly needed recovery action depends on the type ofthe faulty object and its current channel configuration.

An automatic recovery procedure is started if the fault makes a whole cellinoperational. Such faults are

. BCCH TRX fault. The BCCH is reconfigured into another TRX if oneavailable.

. TRX fault in a baseband hopping cell. The frequency hopping parametersare recalculated for all the remaining TRXs of the cell.

If there is a preferred BCCH mark on some TRX, the BCCH is reconfigured tothat TRX. Forced handovers are used to clear the reconfigured TRX(s) in order toavoid cutting any calls. After the faulty unit has been repaired or replaced, thefailure is cancelled and the radio network configuration management systemallocates the related resources back to service. Also, if the BCCH functionality isnot on the preferred BCCH marked TRX, the BCCH functionality is returned tothat TRX.

For more information, see Radio Network Recovery and State Management.


5.22 Remote BTS MMI

To minimise the need for site visits, it is necessary that the BTS-MMI functionsare accessible also remotely.



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The remote BTS-MMI feature offers a BTS-MMI interface at the BSC site. A PCwith the BTS-MMI software is used as a user terminal. The PC is connected viaRS-232 cable to a service terminal interface of the Operation and MaintenanceUnit (OMU) of the BSC. All the same functions of the BTS-MMI are availableremotely as are locally at the BTS site.

The same MMI software in the PC is used when the PC is connected to the BSCand when it is connected straight to the BTS. Thus the same PC equipment, forexample, a laptop, is usable at the both ends.

The same set of functionality as from the BSC site is also available from NokiaNetAct site. HW database upload/download from BSC disks is not possible, thisrequires local connection from the MMI to the BSC.

For more information, see BCF Remote MMI.


5.23 Safecopying of files

Duplicated hard disks with back-up and fall-back versions of software packagesensure redundancy for files in the system, but it is also possible to make safe-copies of files manually either to 3 1/2" (floppy) diskettes, to Nokia NetAct FrontEnd or to DAT tape (optional).

The following files copying operations are available:

. from one disk directory to another

. between the system and back-up disks

. between the hard disk and the diskettes of 3 1/2"

. between the hard disk and the DAT

The copying can concern one file, but it is possible to copy whole directories ordirectory structures (for example, software packages) with one command. Thesource and target devices of the copying can reside in different systems of theO&M network.

The operator has a set of MML commands for the copying. Also, the defaultdirectories of copying can be set with commands. In addition to the system disks,the copying commands can be directed to diskettes and tape units.





5.24 Security reporting

A logbook function is needed in tracing, saving and repeating actions of MMLsessions. By the security reporting the BSC gathers all the MML commandsgiven by the MML operator and the command responses into a user specific fileon disk.

With the help of the MML session log files the operator can handle the MMLcommands that they have entered earlier. The stored data can be scanned andprocessed, and the MML commands can also be re-run, if required.

The commands given during one day are stored into the same file. The files canbe identified on account of the username and the date of the MML session.

. storing of given MML commands into user specific files

. sending of information onto the alarm printer when an MML terminal isactivated

. setting an alarm about attempts to open an MML session with anunauthorised username

There is an option to use security counters. These counters provide informationon users and commands used (not on parameters within commands), and onwhether the commands were successful or not. The purpose is also to give analarm to the operator if specified counter limit is reached.


5.25 Serial and version number storage

The unit version and serial numbers can be locally stored into the non-volatilememory of BTS. Information must be manually entered to the BTS with the helpof the BTS MMI. A light pen can be used to read the bar codes attached to theBTS units. Stored information can be later retrieved and changed with the BTSMMI if, for example, configuration is expanded or units are replaced. This way itis possible to have an up-to-date bookkeeping of site unit identifications.

In Nokia 2nd generation BTSs the serial and version number information is a partof the HW database file. In Nokia Talk-family and Nokia PrimeSite BTSs,information is stored into separate file that can be handled independently from theHW database. This enables database file sharing between different sites havingexactly the same HW configuration.



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The stored data includes unit name, generation and version of the unit, hardwareand firmware versions, serial number and the location information. The actualuser interface of this feature is at Nokia NetAct. There are several alternatives onhow to filter or selectively retrieve information concerning certain sites, units,versions etc.


5.26 Transcoder configuration management

The transcoder configuration management allows the operator to manage thetranscoder remotely. The operator can manage transcoder configuration andthrough connections.

It is also possible to modify TC-PCM type between types that use the samesubmultiplexing scheme in the TCSM, which are as follows:

. two bit channels in Ater:

FR - FR&HR - EFR &FR - EFR&FR&HR - EFR&FR&HR&D144(circuit pools 1, 3, 5, 7 and 20 )

. four bit channels in Ater:

HS2 - HS2&D144 (circuit pools 10 and 21)

. eight bit channels in Ater:

HS4 - HS4&D144 (circuit pools 13 and 21)

The Half Rate PCMs cannot be changed because there is no other TC-PCM typethat only uses one bit per channel in Ater.

For more information, see BSS Transmission Management .


5.27 Transcoder software downloading

This feature provides the means to download the software package of the DX200Transcoder Submultiplexer (TCSM2) from the BSC. With this feature theoperator can easily install a new software package in the TCSM2 units.




The TCSM2 software is a part of the BSC SW package. The DX200 softwareconfiguration management features and MML commands can be used also withTCSM2 SW as with other BSC SW modules.

The new SW package is loaded down when a TCSM2 is restarted and the SWversion check or checksum check fails. Restarting with SW loading can be alsoforced with an MML command regardless of the checking.



5.28 Alarm if number of usable A-If circuits below limit

A-interface circuit availability supervision measures the number of unavailableA-interface circuits. If the number of unavailable circuits exceeds the predefinedlimit and stays above that limit for a certain period of time an alarm is given to theoperator.

A-interface circuits are either available in the WO-EX state or unavailable in allother states. The only exception is the NU-US state, which is considered neitheravailable nor unavailable, because this is not a normal operational state forcircuits.

The following factors can bring about the BL (blocked) state:

. the user has blocked the circuit

. the user has blocked the exchange terminal

. the system has blocked the circuits due to 2Mbit failure

. the system has blocked the circuit due to transcoder supervision (Q1)alarm

This feature is controlled by two parameters. The first parameter is the alarm limitgiven as a percentage of unavailable A-interface circuits. The given value iscommon for all A-interface circuits and does not depend on different circuitgroups defined in the A-interface. The second parameter is alarm delay. That isthe time during which the alarm conditions must be fulfilled before the alarm isset. The supervision can be turned off by changing the first parameter value to100%.




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5.29 BCCH supervision

The continuous transmission of a BCCH is essential for services. Therefore,there has to be means to supervise that transmission really takes place.

In Nokia 2nd generation of BTSs the RTC (Remote Tune Combiner) can detect asituation when there is no power input to a cavity. After downloading, when theBTS-OMU informs the BSC about the state change of a BCCH-TRX, the BTS-OMU starts a timer. If this timer expires before there is a cancellation to the 'nocarrier' alarm from the RTC, an alarm NO BCCH TRANSMISSION is sent to theBSC.

In Nokia Talk-family, similar logic exists, but here the supervision is availablealso with wideband combiners.


5.30 BSC external alarms and controls

The HWAT plug-in unit (Hardware Alarm Terminal) contains 24 interfaces forincoming external alarms and 16 interfaces for outgoing external controls.

With MML commands the user can, for example, create and remove externalalarms, modify alarm text and print out required external alarms.



5.31 BSC system maintenance

System Maintenance handles all fault situations and user-initiated configurationmanagement tasks in the system hardware and software by meeting all theavailability performance requirements for the whole system and for individualcustomers.

Fault tolerance is a general requirement set for all software in the DX 200 BSCnetwork element, but this system feature is controlled especially by systemmaintenance.




System maintenance is responsible for availability performance on the networkelement level, and it should perform its task as automatically and autonomouslyas possible. Thus, a network element can be maintained remotely, except in caseswhen it is necessary to perform a physical action on the hardware.

All MML commands involving system maintenance can be used locally as wellas remotely from Nokia NetAct exchange.

Supervision

System supervision is a function group , which consists of hardwaresupervision, software supervision, semipermanent connections supervision andreal time supervision.

Hardware supervision

Hardware supervision is based on routine tests and on continuoussupervision executed as a background process. Hardware supervision isdivided into supervision of microcomputers and supervision of switchingnetwork.

Microcomputer supervision is executed in all computer units as a backgroundprocess so that the normal operation of the unit is not disturbed. Also thesupervision of all switching networks in the DX 200 system is executed as abackground process without disturbing the call traffic and by using the testingproperties integrated into the switching network.

Supervision of software

Supervision of the software reveals fault conditions in which the control of thesoftware is lost. The supervision is based on watch-dog timers and specialsupervision messages. All control processors and pre-processors of the systemmust set their watch-dog timers at predefined intervals, otherwise the hardwarerestarts the processor.

Supervision of semipermanent connections

Supervision of semipermanent connections ensures that the connections definedby user commands are maintained in the switching network. If a connection thathas already been defined is for some reason missing, is redefined. If therestoration of the connection fails, or the connection disappears for the secondtime, an alarm is generated.

Supervision of real time



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Supervision of real time is executed in a hierarchical manner so that NokiaNetAct supervises the real time of the systems that are directly below it in thenetwork hierarchy. At the level of network, the OMU supervises the time of theother units.

If the time of a system under Nokia NetAct differs from the times of the othersystems more than 5 seconds, the system time is corrected so that it is the sameas the time of the supervisor, or an alarm is given to the user to check thesituation.

Alarm functions

The tasks of the alarm system are to collect the various fault observations, toprocess them, and to inform the user with suitable alarm printouts and alarmlamp panel controls. Normally, the BSC has a lamp panel, but the control outputscan also be used for other purposes. Furthermore, the alarm system stores thefault observations, and the conclusions made on the basis of them, and starts upthe automatic recovery functions when necessary.

The alarm system tries to localise the fault or disturbance to a specific functionalunit.

Alarm functions include

. collection of alarm data

. storing of alarms

. output of alarms

. control of alarm outputs

. activation of recovery functions in connection with a unit failure

. starting of an MML sequence of the command calendar for predefinedfaults

The alarm functions have a user interface to the functions, which control the set-up of alarm parameters, the examination of the alarm situation and alarm history.Alarm-specific printout control. The new MML commands are used to block andunblock local printing and the sending of alarms to Nokia NetAct.

Rule base

By means of a rule base, the behaviour of alarm system can be tuned to serve bestthe operators needs and requirements. As an example, if the fault or disturbanceobservation occurs repetitively a higher class ( 2615 ** or 2616 ***) an alarm isautomatically sent by the alarm system.




Recovery

The task of the recovery block is to control the operating states of the functionalunits. The recovery functions are

. elimination of the effects of faults

. restart control

. user interface

The faults are eliminated by means of the hardware redundancy. On thefunctional unit level, processor and pre-processor restarts are also used.

Recovery has in its possession real-time data about the states of the functionalunits. Using this data, it controls the restarting of the system and of its functionalunits so that the restarts are carried out in the correct order quickly and reliably.

With the recovery interface commands, the whole system or its functional unitscan be restarted, the states of functional units can be changed and variousinquiries about the states of the units can be made.

The recovery system consists of a centralised part, situated in the OMU, or in thecase of an OMU failure, in the MCMU unit; and of a distributed section in eachcomputer unit. The centralised part controls the recovery of functional units as awhole, and the distributed part is responsible for the actions at unit level. Therecovery system is implemented so that several recovery actions can be executedin the system simultaneously.

Fault recovery

A unit failure notice from the alarm system functions as an impulse for the faultrecovery. A recovery action depends on the type of the unit to be recovered andalso on the overall condition of the system. For instance, if the active unit of aduplicated unit type fails, either a changeover is made or the operating personnelis called for help, depending on the availability (state) of the spare unit. Intimeslot-based units the recovery is responsible for preserving a certain minimumconfiguration of the unit type in question in the system at all times.

One of the general principles is that a failed unit is taken to the test state and faultlocalisation and testing programs are activated. On the basis of the diagnosis, theunit is taken to the separated state (fault detected) or taken automatically into use(no fault).

Fault location



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The task of the fault location function is to refer hardware faults in the system toone plug-in unit in 70% of cases and to four plug-in units in 95% of cases. Thesystem complies with the CCITT requirement about the average active repair timeof 30 minutes.

The fault location function has been implemented for every functional unit(including TCSM2). The function can be divided into the following subfunctions:

. fault location for switching network

. fault location for processor units

. fault location for timeslot-based units

. fault location for pre-processors

. fault location for I/O devices

. fault location for message bus and supervisory bus

. fault location for clock system

There can be several diagnostic tasks in progress in the system at a time. In thediagnostic job queue, there is room for ten tasks, which can either be running orexpecting a certain resource. In addition, the user can place a job with priority inthe queue.

With the commands of the diagnostics handling MML program, the operatorcan start the diagnostics for a functional unit or an I/O device, output individualtests of a functional unit, output the faulty units of the system (either all of themor just the faulty processor units), inquire the current test and the waiting tests andinterrupt the current test. The last command also facilitates the setting of a holdtime during which no diagnosis tests are started automatically.


5.32 BTS-TC connection establishment supervision

The purpose of BTS-TC connection establishment supervision is to providemeans to observe faults in alignment between TRXs and individual TC channels.An alarm is generated on those circuits that cannot carry traffic. TheCONNECTION FAILURE message from the BTS with a cause 'remotetranscoder alarm' is supervised per circuit between BTS and TC, A and Abisinterface.




If a certain number (threshold can be set using the MML in A-interface) ofsuccessive call attempts fails on one circuit, an alarm is written to the local alarmprinter. Nokia NetAct is informed of the event as well. The reason for the failuremust be the same every time: REMOTE TRANSCODER FAILURE. When thishappens, it is evident that the circuit is the reason for the failure in connectionestablishment.

This feature is complementary to the TC supervision function (supervision by theTCSM, alarms via Q1 bus). TC supervision supervises individual TC channels.These features together make it easier for the operator to find out someconfiguration errors (for example, routing and semipermanent connections).



5.33 BTS external alarms and controls

A BTS site usually contains some additional equipment (battery back-up systems,rectifiers, radio links, cooling systems etc.) that are vital to the site operation andtherefore need some kind of supervision and alarm monitoring support. Similarneeds exist for controlling some site equipment.

The BTS cabinets support external digital inputs and outputs for controlling someexternal devices and for collecting alarm information. The actual number of linesavailable depends on the cabinet type in use. The state of outputs can becontrolled from the BSC-MMI and they are also initialised to the desired statealways after a site reset.

The user can define the following characteristics for all external inputs into thehardware database:

. descriptive text string, for example, "SITE DOOR"

. active state definition, that is, polarity. This defines whether an alarm israised when the input is grounded or disconnected from ground potential.

. fatality of the alarm

The state of inputs is reported as alarms to the BSC (and to Nokia NetAct). Everytime a change in the state of any of the inputs takes place, the identity, theattached text and the new state of that input is reported to the BSC (and to NokiaNetAct) as an alarm.




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5.34 BTS testing in BSC

BTS testing in the BSC provides the user the means of checking the operationalcondition of the base station system. BTS testing principles are divided into threeparts:

. commissioning

When new equipment is installed to the network, its functionality can beverified by testing. Tests can be done as single tests on the BTS site by theBTS-MMI or remotely from the BSC site by MML's.

. monitoring

Monitoring means preventative maintenance, which can be carried outwith scheduled BTS tests. With these tests, faults can be found before theycause traffic problems. The threshold for the test result (pass/fail) isadjustable.

. fault diagnosis

With fault diagnosis, faults can be located to a specific part of the basestation system or BTS.

The BSC keeps a test report history of the tests, which are executed, via theBSC's MMI user interface. The results can be printed out on the MMI screen withMMI commands. One result per test object is saved. Depending on the test type,the test object can be either BTS or TRX . Only the latest test result of an objectcan be seen.

The tests can be performed by a Radio Frequency Test Equipment (RFTE) or aSite Test Monitor unit (STM). The RFTE is capable of performing a loopingfunction on the RF signal. It loops the transmitted signal back to the receiver ofthe BTS thus making it possible to monitor the condition of the common RFunits.

The STM has a standard Nokia mobile phone integrated in an STM unit. TheSTM unit is an option in the BTS and when used it replaces the RFTE. For NokiaTalk-family and Nokia PrimeSite BTS's there are also tests which do not requireany specific test equipment.




STMA is an older version of the STM unit. STMA is not available anymore. Ithas been replaced with STM version, the STMB/C/D/E. STMB is for Nokia 2ndgeneration (GSM 900), STMC is for Nokia 2nd generation (GSM 1800), andSTMD is for Nokia Talk-family (GSM 900) and STME for Nokia Talk-family(GSM 1800). STMP is a portable STM. The STMP is used in commissioning andtesting Nokia FlexiTalk DE 34/ DF 34 BTSs. As there is not enough space for theSTMD/E unit in the Nokia FlexiTalk, the STMP must be used to connect theSTMD/E unit to the BTS.

The following table clarifies what equipment is needed in different types of sitesin order to carry out certain BTS tests.

2nd GenGSM 900

2ndGenGSM1800

Talk-family(GSM 900)

Talk-family(GSM1800)

Prime Site

TRX Testby Cable

RFTE orSTMA orSTMB

RFTEorSTMC

STMD STME �

TRX Testby Air

STMA orSTMB

STMC STMD STME �

RXAntennaTest

RFTE orSTMB

� STMD STME

TRX LoopTest

� � No testequipment

No testequipment

No testequipment

AntennaLoop Test

� � � � No testequipment

MOC STMA orSTMB

STMC STMD STME �

MTC STMA orSTMB

STMC STMD STME �

BCCCHFieldStrengthMeas.

STMA orSTMB

STMC STMD STME �

ReceiverSensitivityMeasure-ment

STMA orSTMB

STMC STMD STME �



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2nd GenGSM 900

2ndGenGSM1800

Talk-family(GSM 900)

Talk-family(GSM1800)

Prime Site

RXAntennaSupervi-sion

RFTE orSTMB

� � � �

A test can be interrupted in a selected BTS. Tests, which are executed by theRFTE, cannot be interrupted. All tests can be run also locally at the site withBTS-MMI.

TRX Test

TRX Test includes:

. TRX test by cable (RFTE, STM

. TRX test by air (STM)

The RFTE or STM loops the RF signal of one radio timeslot through both thetransmitter (via the possible combiner) and the receiver without causing anydisturbances to other channels. The TRX test shows how the transmitters andreceivers work.

The RFTE or STM loops the RF signal of one radio timeslot through both thetransmitter (via the possible combiner) and the receiver without causing anydisturbances to other channels. The TRX test shows how the transmitters andreceivers work.

RX Antenna Test

The RX antenna test shows the condition of the receiver antennas. Test is similarto the single TRX test by cable, except that it is based on two loops. In the firstloop, signal is forwarded to the BTS receiver. The first loop is a reference test forthe second loop. In the second loop, a directive coupler is controlled to feed a RFsignal towards RX antenna. Now the signal that BTS receives is the signalreflected from the cable and antenna. By comparing the test results of these twotests, it can be found out what is the matching of the RX antenna. In perfectmatching, no signal should be reflected from the antenna. The test can be definedin the same way as a TRX test.

This test is available in Nokia 2nd generation BTSs only for GSM 900.

TRX Loop Test




In TRX loop the test data generated by SW in digital parts of the TRX is loopedfrom TX to RX side inside the TRX so that the complete TX and RX chains aretested. The looped data is checked by TRX SWand the test result is given as BERvalues. The looping is done with a mixer, thus the three timeslot delay betweentransmission and reception is not implemented. Therefore, two timeslots need tobe reserved for this test, one is used for transmission and another for reception.Timeslots are selected by the system in such a way that transmission andreception overlap in time. The TRX loop can be executed only in TCH/FRtimeslots.

If Base Band Hopping is used, sets some limitations to the use of the loop. Boththe timeslots reserved for the loop must use exactly the same hopping sequence,otherwise the data transmitted is never looped back to the originator.

The test can be performed only by Nokia Talk-family and Nokia PrimeSite BTSs.The test does not require any special test equipment in the BTS.

Antenna Loop Test

The functions of the antenna loop test and TRX loop test are very much alike.The test data generated by SW in digital parts of the BTS is looped from TX toRX via air interface thus the complete TX and RX chains are tested. The loopeddata is checked by TRX SW and the test result is given as BER values. TheVSWR of the transmitting antenna is also measured. The antenna loop canexecuted only in TCH/FR timeslots.

The antenna loop test can be performed only by Nokia PrimeSite BTSs. The testdoes not require any special test equipment in the BTS.

Scheduled TRX Test

By the scheduled TRX test it is possible to run the TRX test, the TRX loop test,the RX antenna test and the Antenna loop test in the selected BTS's. Naturally, theselected BTS must support the test type.

The user creates the scheduled TRX test in Nokia NetAct.

Nokia NetAct user can create 15 scheduled TRX tests to the same BSC so forexample different BTS generations can be tested with different test parametersand schedules.

Originating Test Call



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In an originating test call the user sends the target phone number to the STM. TheSTM makes a call to the specified number. When the operator answers the phone,the operator can hear that the speech path is open as the STM loops the speechback. Call status information is reported from the BTS to the user. Callinformation can be inquired several times during the call. In the test request, theuser can define the BCCH's (broadcast control channel) ARFN (absolute radiofrequency number) that are used in the test call.

Scheduled Originating Test Call

Originating test calls can also be executed as a scheduled test. The test makesoriginating test calls through selected BTSs. If the test call fails, an alarm is setfor the concerned BTS. Data on successful and unsuccessful calls is collected totraffic measurement counters, which are updated during the test. A scheduled testcan be managed by the MMI commands.

In a scheduled originating test call, the user can define the BTSs, which are testedperiodically by the test call. BTSs can be defined as main BTSs (the ones whichhave STM) and subBTSs (main BTS's adjacent BTSs). One main BTS can have10 subBTSs to be tested. It is possible to define 10 scheduled MOC tests perBSC. The tests are managed by the MMI commands.

Terminating Test Call

The terminating test call test shows if the BTS works in general. This test can beperformed by making a call to the STM, which loops the speech back to theoperator's phone. Before the test, the STM can be synchronised to the givenBCCH ARFN. When the call is on, the operator can ask information about thecall in the same way as in the originating test call. Information can be asked forseveral times during the test. Test information will be reported from the BTS tothe user.

BCCH Field Strength Measurement

The BCCH field strength can be measured from the selected BTS. The measuredBCCH's ARFN can be given in the test command. The STM measures theselected BCCH ARFN signal strength.

Receiver Sensitivity Measurement

Receiver sensitivity is measured by the BTS. The BTS sends data to the STMthrough the cable connection. The STM loops the data back and the BTScalculates the RBER2 (2nd class bit error ratio) value. The STM changes thepower level of the transmitter of a mobile until the specified RBER2 level isachieved. Test results are reported to the user.




The receiver sensitivity measurement can also be executed as a scheduled test. Ifthe test fails BSC sets also an alarm in addition to the test report.

The scheduled test can be created, started, stopped, modified and deleted and theresults can be interrogated with BSC's MML.

RX Antenna Supervision

The Nokia 2nd generation BTS can perform an RX antenna test periodically(RFTE or STM is required). User can define the period in minutes with a BSCMML. If a fault is detected, the BTS sends an alarm to the BSC.

TRX Test for the Nokia MetroSite Base Station

This test is meant for testing the total performance of the intended TRX andRadio Time Slot (RTS). The test covers all the functions between the Abis andAir: Digital and RF parts, VSWR for antennas, RX sensitivity and TX level.

The main reason for providing a single multipurpose test is to minimise the totaltest time, once the timeslot is reserved for testing, the test time is used effectively.This test uses the multifunctional RF loop. The test is automatically performedfor both RX branches. The test time is a couple of seconds. This test can be usedas a RF-performance supervision test when performed according to regularschedules from Nokia NetAct.

TRX Test for Nokia UltraSite EDGE BTS

This test is for testing the total performance of the intended TRX and Radio TimeSlot (RTS). The test covers most of the functions between the Abis and Airinterfaces: Digital and RF parts, RX sensitivity and TX level.

The main reason for providing a single multipurpose test is to minimise the totaltest time.

When the TRX test is carried out according to a regular schedule it can be used inTRX performance supervision.

Both RX branches are tested separately during the same TRX test. If diversity isnot configured the main branch only is tested.

The power level during the TRX test is the same as the BCCH power level. Toavoid unwanted disturbances to the TRXs the training sequence is not the same asthe one normally used.

All TRXs in a BTS can be tested either remotely from the BSC, Nokia NetAct, orlocally with Nokia BTS Manager.



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Note

The TRX test can be performed only in TCH timeslots. Two free timeslots areneeded for the test. TRX test is not possible when baseband hopping is used.

Abis Loop Test

Abis loop test is performed in order to check the Abis transmission has beenproperly set up (after Autoconfiguration for Nokia InSite BTS), the quality of theAbis transmission and to trace possible transmission problems in the Abisinterface. Automatic testing consists of TRX testing and the testing of Abistransmission. Abis Loop Test is in charge of testing Abis transmission. Maintasks of the Abis loop test are to ensure that Abis connections have been madeproperly and that the quality of the connections is sufficient.

The Abis loop test starts when the Nokia MetroSite Base Station receives thetesting request manually by the MML or by the commissioning wizard. A testingrestriction is that control channels can only be tested during commissioning. ForNokia UltraSite BTS, the Abis loop test starts when it receives the testing requestmanually by the MML. For Nokia InSite BTS, the Abis Loop Test starts when itreceives the testing request manually by MML or during the AbisAutoconfiguration procedure. A testing restriction is that control channels canonly be tested during autoconfiguration.

For more information, see Radio Network Testing.


5.35 GSM trace

The aim of tracing is to start a log of all or some events happening during acertain period of time. This is particularly useful, when subscriber (IMSI)observations are needed, for example, when the MS is suspected to be faulty.

The trace facility is a useful aid in maintenance. It is also a development tool thatcan be used during system testing etc. In particular it may be used in conjunctionwith test-MSs to ascertain the digital cell "footprint", network integrity and alsothe network Quality of Service (QoS) as perceived by the PLMN customer.




The trace facility enables the NM to trace activities of IMSIs that result in eventsoccurring in the PLMN. This facility also enables the tracing of all theinformation, that is available within, or accessible by the PLMN, on the call pathused by the associated MS, that is the BER of the radio uplink and downlink, theidentity of originating and terminating equipment of the mobile or fixedsubscriber, the identity of incoming and outgoing circuits in the nodes involved.

The route information facility is a useful maintenance aid. It enables networkmanagement to trace the actual hardware route of a call. Information from traceand observation reports can be used to solve suspected hardware problems withina BSC.

The trace report has additional HW information called Route Trace Data. Theinformation includes:

. A-if ET-PCM, ET-TSL and ET-SUB-TSL

. Abis ET-PCM, ET-TSL and ET-SUB-TSL

. SPC, CIC, Transcoder PCM and TSL

. Group switch type and BCSU id

There are several new fields in the GSM ph2 trace invocation message over theA-interface ('MSC invoke trace'). Of those the following actions will beimplemented:

Priority output

If the MSC orders the BSC to use priority output for trace reports the BSC sendstracing data as Q3 events immediately to Nokia NetAct.

Normal output

tracing data goes to performance data files.

Events including/excluding radio measurements

the BSC includes or excludes radio measurements in tracing reports




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5.36 Hot spot location

With Hot spot location measurement, the operator discovers where the majorityof the subscribers are located in the cell's coverage area. The places where morecapacity is needed can be predicted. The locationing is based on the timingadvances of the three best adjacent cells reported by the mobiles during the calls.One cell under one BSC can be measured simultaneously. The BSC fills theappeared triplets of adjacent cells and the distribution to different timing advanceclasses to a table.

The BSC reports ten most frequently appeared triplets and the distribution totiming advances to Nokia NetAct after each measurement interval. The operatorwill get the most out of the results of this measurement with the post processingtools in Nokia NetAct Planner.


5.37 PM file compression

The amount of data to be sent to Nokia NetAct as PM counters is quite high, agreat amount of the data is zeroes. A compression algorithm remarkably reducesthe amount of data to be transferred.

The algorithm used is based on Public Domain compression algorithm SW.Compression can be switched off.


5.38 Radio network maintenance

Radio network maintenance in the BSC provides facilities for maintaining theoperational status of the radio network system when faults occur in the basestation system (BSS).

In addition to detection of faults in the BSS, the feature includes automaticoperations that minimise the effect of faults on the quality of the service. Theuser is informed of these faults by alarm print-outs (alarm reports).

BTS Alarm Handling in BSC

The alarm handling system receives alarm indications from the following sourcesin the radio network:




. alarms from the BTS equipment

. external alarms from the BTS site

. alarms concerning PCM lines in the radio network

. alarms from LAPD links on the Abis interface

. alarms from Abis interface equipment

. alarms from BSC application programs

The alarm handling system informs the user of the faults by actual alarmprintouts. Moreover, the alarm handling system makes decisions on the basis ofalarm indications and activates the radio network recovery when needed, so thatthe automatic recovery actions are started.

When there are multiple fault indications, the alarm handling system will attemptto eliminate all other fault indications except the actual one. Other faultindications may be blocked, if a more critical fault has arrived and is still inprocess. This procedure is needed in case of alarm bursts.

With the MML interface, the user can:

. block and unblock alarms & list blocked alarms

. change alarm class

. cancel alarm

. list alarms currently on

. list alarm history

BCF Maintenance Mode

The main idea of the feature is to provide a way to separate a particular site fromnormal alarm surveillance. This makes it possible to "isolate" a site, for example,which is having problems concerning subsequent alarming or a site, which is stillin the hands of commissioning/integration teams.

The BCF maintenance mode allows the user to block or modify BTS alarmhandling of a specified BCF. This can be done by MML commands. Themodifiable parameters are:

. recovery

. local print-out



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. Nokia NetAct updating

. blocked

The first three have the values ON and OFF. Blocked means that all thesefunctions are disabled and alarms are not handled at all.

When recovery is disabled and then enabled with MML, the default action of thealarm system is to restart the BCF, because some recovery actions may have beenlost during maintenance mode.

When one or several parameters are in the state OFF the alarm BCFMAINTENANCE MODE is active.

BTS Fault Recovery in BSC

BTS recovery in the BSC minimises the effect of faults in the radio network onthe service level provided by the BSS. In addition to performing fault originatedrecovery actions, the BTS recovery controls initialisations when there are resetsand restarts in the BSS radio network. The latter includes phasing activities insoftware and configuration loading.

The type of recovery action depends on the type of the faulty unit (for example,the FU or CU) and its current channel configuration. When there are multiplerecovery inputs, the BTS recovery system tries to eliminate all other recoveryrequests except the actual one. The other recovery requests can be blocked orignored if a more crucial fault or initialisation has occurred and is still under way.

After the faulty unit has been repaired or replaced, and the operating personneltakes it back to use or the system cancels the failure, radio network configurationmanagement allocates the related resources back to call control purposes.

The BTS recovery system is activated in the following cases:

. DSP/TSL fault

. TRX fault

. BTS fault

. fault covers the whole BTS site

. failures in transmission network

. TRX local blocking/deblocking

. initialisations (resets) in BSS radio network

. restarts by user commands




For more information, see Radio Network Maintenance.


5.39 TX antenna VSWR supervision

All combiners are capable of monitoring the VSWR (Voltage Standing WaveRatio) at the combiner output. This monitoring is a continuous procedure andfully automatic. Two levels of indications are provided, lower and upper. Thethreshold for upper indication is 3.0 and for lower 2.3. With the RTC, thethreshold for the lower indication can be set in range from 1.6 to 3.0. This is notavailable with wide band combiners. When either of the level is exceeded, thecombiner raises an alarm and the BCF then sends the alarm to the BSC, whichthen takes the necessary recovery actions. When the lower level is exceeded, thealarm is non-fatal and service can continue. When the upper level is exceeded, afatal alarm is raised.

In Nokia Talk-family of BTSs the monitoring of the antennas in dual duplexconfiguration are organised as follows:

The VSWR of the antenna carrying the BCCH shall be monitored during normaloperation. The other antenna does not have a continuous transmit signal, which ismandatory for the VSWR measurement. Therefore the BCF must start acontinuous fixed level transmission on one of the TRXs connected to the otherantenna. When the measurement is completed, transmission is switched off. Thetransmission power used during the test is the BCCH power defined for this cell.

The above covers the antenna supervision when Base Band Hopping is not used.When it is used, it is necessary to activate transmission in all TRXs belonging tothe same hopping group in order to ensure continuous transmission in theantenna. Otherwise the procedure is the same.


5.40 Radio network supervision

Radio network supervision provides the operator with information about thefunctioning and usage of TCHs and SDCCHs in the BSC. This information isrelated to mean holding times that are too long or too short, traffic channelinterference levels, channel failure rates, SDCCH and TCH congestion and BTSswithout traffic transactions.



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The information is available for the operator from the alarm system of the BSC,which generates alarms according to the input from the BSC call control.

The BSC supervises the TCH and SDCCH transactions by measuring callduration and observing different events related to these transactions. At the endof each measurement period the BSC compares the values of different counters,which have been stored in its BTS, and channel-specific files to thecorresponding threshold values set by the operator.

All the parameters associated with radio network supervision are BSC specificand can be defined by the operator. These parameters define the alarm thresholdsand the length of the measurement periods for the different supervisions. Thesupervisions are activated and deactivated by modifying these threshold valuesand measurement period lengths.

Once the supervision is activated, the supervision is continuous frommeasurement period to another as long as the supervision stays active. Anexception to this is the supervision of BTSs with no transactions, which has dailystarting and stopping times.

For more information, see Radio Network Supervision in BSC.


5.41 C/I ratio statistics (C/I)

The purpose of the C/I (carrier/interference) ratio measurement is to estimate thelevel of the co- and adjacent channel interference in the radio network. Theinterference estimation is based on the measurement results reported by the MSvia the BTS. The C/I ratio measurement helps the frequency planning of the radionetwork.

The C/I ratio statistics measurement collects statistics of the degree of theinterference by measuring traffic intensity (in Erlangs) on a specified C/I ratioband.

The object of the C/I ratio statistics measurement is one specified cell and onespecified C/I ratio band. The object cell of the measurement is called a test cell.The C/I ratio statistics measurement measures the traffic intensity on the observedC/I ratio band (the part of the traffic where downlink/uplink C/I ratio is within theobserved C/I ratio band) by monitoring continuously every call which is ongoingin the test cell and in its interfering cells. The interfering cells are composed ofeither all adjacent cells of the test cell or a maximum of 6 specified adjacent cellsof the test cell.




When the test cell is a serving cell, the measurement monitories the downlink C/Iratio of the test cell by comparing the downlink signal level of the test cell(carrier) and the downlink signal level of each interfering cell (interference) on acell-by-cell basis. The measurement also monitories the uplink interference whichthe call on a channel in the test cell causes to each of the interfering cells.

When an interfering cell is a serving cell, the measurement monitories thedownlink C/I ratio of the interfering cell by comparing the downlink signal levelof the interfering cell (carrier) and the downlink signal level of the test cell(interference), and the uplink interference which the call on a channel in theinterfering cell causes to the test cell.

For more information, see Intelligent Underlay-Overlay.


5.42 CCCH load statistics

The Common Control Channel (CCCH) is responsible for transferring the databetween all mobiles and the BTS. This is necessary for the implementation of callorigination and call paging functions. The CCCH consists of the following:

. Random Access Control Channel (RACH) is the uplink used for gainingaccess to the system when initiating a call or responding to a page.

. Paging channel (PCH) and Access Grant Control Channel (AGCH) operatein the downlink direction to the mobile. The PCH is used to page an MSfrom the system.

The AGCH is used to assign dedicated resources to an MS such as a StandaloneDedicated Control channel (SDCCH).

The CCCH load statistics gives information about paging and RACH load.Statistics can be used for example to indicate when there is a requirement forchanging of parameters number of blocks for access grant msg (AG)and number of multiframes (MFR).

This feature is an enhancement to the Resource Access measurement. Nextcounters are added:

1. Maximum paging buffer capacity

This counter indicates maximum paging buffer occupancy percentageduring the reporting period.



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2. Average paging buffer capacity

This counter indicates average paging buffer occupancy percentage duringthe reporting period.

3. Delete paging command

This counter tells the number of the delete paging commands.


5.43 Administration of measurements and observations

Most of the measurement types are needed only during some periods during aweek or a day. For these measurement types the produced data amount has to belimited by means of time schedules. Administration of performancemeasurements and observations offers a possibility to use different time schedulesfor each measurement and observation type.

This feature allows the following operations to be executed for each individualmeasurement and observation type: Modify, Interrogate, Start, and Stop. Eachmeasurement and observation type has the following attributes: schedule(recording days within the week, up to 3 recording periods within recording days,output interval), start/stop dates, measurement objects (these depend on themeasurement type: cell, computer unit, channel), administrative state (locked,unlocked) and operational state (enabled, disabled).

When the operator creates a new measurement the parameters concerning themeasurement periods are:

Days (Monday, Tuesday, etc)

Periods during the days, max three

Output interval (15min, 30min, 60 min, 2h, 3h, 4h, 6h, 12h, 24h)

With this feature it is possible to define an own output interval for each threeperiods, for example:

MEASUREMENT TYPE:TRAFFIC

MEASUREMENT PERIODS:




MON00:00 - 06:0006:00 - 18:0018:00 - 24:00

TUE00:00 - 06:0006:00 - 18:0018:00 - 24:00

WED00:00 - 06:0006:00 - 18:0018:00 - 24:00

....

SUN00:00 - 06:0006:00 - 18:0018:00 - 24:00

OUTPUT INTERVAL:6 hours

60 min

2 hours

The measurement periods and output intervals are the same for each week day (itis not possible to create different measurement periods and output intervals, forexample, weekends).

The feature is implemented as described in the GSM900/1800 recommendation12.04.

Nokia NetAct gets EVENT information when the measurement is started andstopped by user using MML

For more information, see BSC Statistics Administration.




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5.44 Handover adjacent cell measurements

The handover adjacent cell measurement collects statistics about the handoverattempts and successful handovers between separate cells. Measurements are notspecific to one reference group.

Statistics are compiled into counters reserved for each BSS cell. Themeasurement is able to maintain information on up to 34 fields per each cell; 32for known handover pairs, one for internal intra-cell handovers and one for over-flowing ( if there are more than 32 handover pairs in the measured cell).

The measurement gives the recorded information about adjacent cells as follows:

1Location area code (LAC) and cell identity (CI) of the adjacent cell

2Handover attempts to adjacent cell

3Successful handovers to adjacent cell

4Handover attempts from adjacent cell

5Successful handovers from adjacent cell

6Failed handovers to adjacent cell due to lack of the radio resources

7Failed handovers from adjacent cell due to lack of the radio resources

The following table presents an example how data collected from cell namedMETRO-15 can be presented.

Adja-cen-tCell

toadja-centcell

fromadja-centcell

attempt success lack attempt success lack

ME-TRO-12

40 35 3 140 136 2




Adja-cen-tCell

toadja-centcell

fromadja-centcell

CITY-3 68 65 1 34 34 0

CITY-7 49 43 5 138 137 0

The operator can define one to four different handover reasons for measurementsand see the success of handovers from one cell to another as regards thesereasons. Information on the success of intra-cell handovers with specifiedhandover reasons are also available. This helps the operator in planning andoptimising the network, by finding the non-successful handover cases.


5.45 MS speed detection measurement

In addition to the handover (HO) measurement counters, HO due to slow MS(macro-micro) and HO due to fast MS (micro-macro) BSC provides also an ownmeasurement to support the MS speed detection feature.


5.46 Underlay-overlay statistics measurements

The underlay-overlay measurement collects statistics about the performance ofthe underlay-overlay procedure. Statistics are compiled in counters reserved foreach TRX.

The information of the underlay-overlay statistics measurement is composed offive parts: identification, traffic measurement, resource availability, super-reusefrequency usability and handover measurement. This measurement is part of theIntelligent Underlay-Overlay feature.


5.47 Radio network optimisation measurements

RX level statistics per TRX (RXLEVEL)



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This measurement shows the RX level in six classes per RX quality band in boththe uplink and the downlink directions.

The measurement consists of 96 counters. There are 48 counters corresponding tothe RX quality bands defined in both the uplink and the downlink directions.

The incrementing is made according to the number of each RX level classreceived by the BSC in the radio link measurement messages. RX level is dividedinto six subclasses in both the uplink and the downlink measurement and theranges of classes are set by the user, for example, 0-10, 11-15, 16-20, 21-30, 31-40, 41-63. In the RX level counter incrementing the missing radio downlinkmeasurement reports and the BTS measurement averaging parameter are takeninto account. If the downlink measurement is missing, the latest downlinkmeasurement is used. This way the counters will be updated every 480 ms.

Link balance per MS classmark per cell (LINKBAL)

This measurement provides the network operator with the path balance, that is,the imbalance between the uplink and the downlink path evaluation.

The path balance difference between the uplink and the downlink path evaluationis divided into 11 subclasses, that is, into five subclasses for negative and positiveimbalance and one for balance. The class ranges are closer to one another near thebalance value 0 and the size of the class is 2 dB while at the edge of the pathbalance range the size of the class is 5 dB. The balance values < -20 dB areconsidered as -20 dB and the balance values > 20 dB is considered as 20 dB. Ifeither the MS or the BTS reports a RXLEV of 63 (-47 dBm), the measurementreport containing this information should be discarded from use within thisevaluation. The path balance is calculated as a difference between the signallevels. Path balance = RxLevDL-RxLevUL-Correction. The correction iscalculated as a difference between the sensitivity levels of the BTS and the MS.Correction = ms_sensitivity - bs_sensitivity. The measurement counters areincremented every 480 ms. In the statistical report the path balance is displayed toan accuracy of one BTS or one BSC.

In path balance counter incrementing the missing radio downlink measurementreports and the BTS measurement averaging parameter are taken into account. Ifthe downlink measurement is missing the path balance is not calculated.

Timing advance statistics per cell (TIMING_ADV)

Timing advance statistics measure the timing advance per MS power. Themeasurement consists of 10*4=40 counters. These counters are incrementedevery 480 ms. In the statistical report the minimum, maximum and average MSpower and the number of the measurement are displayed per timing advance classto the accuracy of one BTS or to the accuracy of one BSC.




Timing advance values are divided into ten subclasses and the ranges of classesare set by the user, for example, the range can be denser in a microcell than in amacrocell.


5.48 RX quality statistics per TRX

The RX quality statistics measurement collects the radio channel quality bandfrequencies. The measurement is compiled of counters reserved for each TRX .

This measurement shows the distribution of traffic on each RX quality bandmeasured by the MSs and BTS on per TRX. The RX quality statistics can be usedto estimate the quality of speech provided by the network.

In both uplink and downlink directions there are eight counters corresponding tothe RX quality bands defined in the Technical specification GSM 05.08.


5.49 Traffic distribution per site (Dual Bandmeasurements)

DUAL measurement shows, how the traffic is divided between the two bands in adual band BCF site. The collected counters are:

. Cumulative TCH holding time of single band subscribers

. Cumulative TCH holding time of dual band subscribers

. Number of TCH reservations by single band subscribers

. Number of TCH reservations by dual band subscribers




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5.50 Standard measurements

In order to run the network effectively, that is, to minimise costs and maximisethe service quality to the subscriber, the operator needs to know certaincharacteristics about the performance and the service level of the BSC and radionetwork. Such characteristics are for example, traffic carried by different cells,congestion on the SDCCH or TCH channels as well as successful and failedhandovers. Traffic measurements provide the required basic information.Standard measurements also include specific counters for some features, forexample, HSCSD .

By analysing the information, the operator can find out if, for example, there areload distribution problems, both heavily and lightly loaded parts in the system. Inthat case the operator can make redimensioning in order to balance the network toimprove the performance. Observing certain traffic characteristics over a periodof time enables the operator to forecast the time when new resources orextensions must be introduced to the network. The measurements are groupedtogether to allow better functionality and handling. This provides the user easierselection of certain measurements necessary at a particular time. Allmeasurements are independent of each other but the same user interface is usedfor handling all measurements.

The measurements include the following:

Traffic measurements per cell (traffic)

Traffic measurement includes SDCCH and TCH counters, for example, seizureattempts, successful seizures and success TCH seizure for assignment complete.Also forced release, forced handover and queue counters belong to trafficmeasurement. The total number of traffic measurement counters is over hundred.

Resource availability measurements per cell (Res_Avail)

The radio resource availability measurement results contain the followinginformation:

. The availability of TCHs and SDCCHs

. The availability of TCHs per interference band

. Time congestion of TCH and SDCCH

. The average and peak number of busy TCHs (Erlang counter) or SDCCHs

. Average holding times of TCH and SDCCH

Resource availability measurements per BSC (Avail_Bsc)




The counter values give averaged information within a measurement period. Thecounters are:

1. Average number of unavailable TRXs due to user actions

The sampled counter is updated, when

. TRX is unblocked

. TRX is blocked

2. Average number of unavailable TRXs due to BSS internal reasons


. TRX is unblocked

. TRX is blocked

3. Average number of unavailable TRXs due to BSS external reasons


. TRX is unblocked

. TRX is blocked

Resource access measurements per Ccch (Ccch_Acc)

The resource access measurement results contain the following information:

. The number of messages per type of message sent via Abis

. The average load on control channels

. The number of seizures for originated and terminated calls

. IMSI detach on SDCCH

. IMSI detach on TCH in FACCH call set-up due to SDCCH congestion

The measurement collects information on the basis of common control channels.

Handover measurement per cell (Ho)

The handover measurement results contain the following information:

. MSC/BSC-controlled incoming handovers succeeded/failed

. MSC/BSC-controlled outgoing handovers succeeded/failed

. Intracellular cell handovers succeeded/failed

. Handovers according to cause



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. Call dropped during external handover after ho command received fromMSC

. Call possibly dropped during external handover after ho request ack sent toMSC

Power control measurement per cell (power)

The power control measurement results contain the following information:

. The number of power control messages sent to the MS and TRX

. The average power of the MS and TRX

. The average Rx quality of the MS and TRX

. The average Rx level of the MS and TRX

. The average uplink interference level on idle channels

Statistics are compiled in counters reserved for each TRX of BSS cells.

OSI/X.25 measurements (OSI)

The OSI measurement results consist of four main parts:

. The results of OSI level 1 (physical layer)

. The results of OSI level 2 (data link layer)

. The results of OSI level 3 (network layer)

. The results of OSI level 4 (transport layer)

The measurement collects information concerning all OSI channels belonging tothe BSC.

Field reporting (Avail)

The availability measurement results contain the following information:

. The number of restarts of a unit

. The number of software process restarts of a unit

. The number of pre-processor restarts of a unit

. The duration of disconnection of a unit

Load measurement (Load)




The load measurement results contain for example:

. The peak value of processor load rate

. The average value of processor load rate

The measurement collects information concerning all computer units belongingto the BSC.

BSC clear codes per call phase per BSC (BSC_CC)

The call is divided into 15 different phases.

. paging/initial ms (ccch and sdcch or tch)

. mm-signalling (sdcch or tch)

. basic assignment (sdcch and tch)

. release (sdcch or tch)

. facch assignment (tch)

. sms-establishment (tch)

. sms-establishment (sdcch)

. ciphering (sdcch or tch)

. external handover (sdcch or tch, source)

. internal handover intra (sdcch or tch, source)

. internal handover inter (sdcch or tch, source)

. external handover (sdcch or tch, target)

. internal handover intra (sdcch or tch, target)

. internal handover inter (sdcch or tch, target)

. conversation (tch)

BSC Clear Code measurement provides all failure and success causes that lead toa channel release in different call phases.

BSC clear codes, PM counters per BSC (CC_PM)

The BSC clear codes PM counters are divided into five different classes:



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. Failure counters

. Success counters

. BCSU counters

. Call establishment cause counters

. Handover counters

These counters provide general information about different channel reservationsat BSC level.

In BSS7 three dx - causes were added (counters for these dx-causes are added inthe BSC clear code (PM) measurement):

1. Attempt IMSI detach

This is incremented when IMSI detach is started.

2. Basic IMSI detach

This is incremented when IMSI detach is done successfully on SDCCHchannel.

3. FACCH IMSI detach

This is incremented when IMSI detach is done successfully on TCHchannel.

BSC clear codes, service level counters per cell (CC_SERLEV)

The BSC clear codes, Service Level counters are divided into two differentclasses.

Failure counters:

These counters are updated after a service level has occurred. The counters aresum counters of different fatal failures that can cause call clearing.

. Call set-up failure

. External handover target failure

. Internal inter handover target failure

. Internal intra handover target failure

. External handover source failure

. Internal inter handover source failure




. Internal intra handover source failure

. Dropped call

. TCH failure

Success counters: The counters for successful signalling.

. External handover target successful

. External handover source successful

. Call successful

. Internal inter handover successful

. Internal intra handover successful

. Set-up successful

. Conversation started

. TCH seizures

The failure and the success counters together characterise the quality of service inBTS level. In BSS7 new call success factors were added:

. Congestion related SDCCH access probability

. Activation related SDCCH access probability

. SDCCH call success ratio

. Congestion related TCH access probability

. Activation related TCH access probability

. TCH success ratio

Transmission measurements

The transmission measurements collect the signal quality counters of theinterfaces of the Nokia transmission equipment.

The counters are based on the G.821 or G.826 recommendation. BSC collects thecounters either through BSCs Q1 channels or if the equipment is connected to theBTS's Q1 bus, through the OMUSIG. There are three different transmissionmeasurements:



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. TRU (Transmission Unit, TRUA and TRUB)

. DN2 (n * 2Mbit/s Dynamic Node)

. DMR (Digital Microwave Radios, Nokia DMR18-38, DMR2000 andDMR7000)

The signal quality counters are:

. total time

. available time

. errored seconds

. severely errored seconds

. degraded minutes

MIN and MAX incoming RF levels are also included to the DMR measurement.

In many cases it is possible to predict the faults appearing in the PCM interfacesdays in advance, based on an increasing number of short disturbances.

BSC and TCSM2 Exchange Terminal plug-in units measure the performance ofthe interfaces permanently in 24-hour periods. The measurement reports of theBSC ETs are printed out locally at midnight. Both BSC and TCSM2 ET reportscan be seen with the MMI commands.

Nokia MetroSite transmission equipment statistics

Nokia MetroSite transmission equipment statistics offers information on thesignal quality of the Nokia MetroSite Transmission system. The Nokia MetroSiteMicrocellular solutions allow greater number of base stations and relatedtransmission equipment. In practice, this means a large set of counters and thusoperator has the possibility to measure the Nokia MetroSite transmissionequipment in two ways:

Firstly, all equipment can be measured with a 24-hour period. This measurementgives fixed set of counters, which are near-end G.826 signal quality counters:

. Total time

. Available time

. Errored seconds

. Severely errored seconds




. Background block errors

. Errored block

Secondly, a certain set of Nokia MetroSite transmission equipment can bedefined. Nokia MetroSite transmission equipment refers to either the wholeequipment or part of it (functional entity and supervision block). It is alsopossible to define the counters that are collected from the equipment. To be ableto do this operator has to know the topology of the transmission network so thathe is able to choose the measurement subject.


5.51 Online observation

Online observation informs about the use of radio network, for example, TCHand SDCCH channels or queued calls. Online observation informs the operator ofradio network usage in the form of events rather than files as do measurementsand other observations.

Radio resource online observation enables the monitoring of radio frequencymeasurements of an MS. It also enables the observation of RF measurementsafter tracing has been set on through the MSC. RX quality statistics of one TRXcan be monitored with the help of this on-line observation.

Before sending the online observation data to Nokia NetAct, the BSC checkswhich version of datatypes Nokia NetAct supports and then makes all thenecessary modifications to the message. After this statistics process, the onlineobservation data is filtered so that Nokia NetAct can understand it regardless ofdatatypes.

A feature that asks for the state of an on-line observation is also implemented tothe BSC. Nokia NetAct can ask whether an online observation is active orinactive, and based on the information this feature is applied or not.




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5.52 BSC observations

BSC observations can be used in obtaining exact information on events in callhandling. There may be events such as abnormal function or traffic pattern incalls on a specific cell or channel, several calls having ended prematurely withoutany obvious reason, inability to establish calls from some location area or systemtesting. The most versatile way of obtaining the required information is to useBSC observation.

BSC observation generates real-time observation records on various occasions.Records are stored on disk files, which can be transferred to Nokia NetAct forpostprocessing. The user can direct an appropriate observation to a desired objectand define the time schedule for that observation.

All observations can be running simultaneously. However, each observation typecan have only one object at a time. There can, nevertheless, be several on-lineobservations active at the same time.

Handover records are made when there are handovers in the observing cell.

The following observation types are available:

SDCCH observation (SDCCH_OBS)

The SDCCH observation report contains information about the SDCCH seizureand release. All SDCCH TSLs for the current TRX of BTS are monitored andidentified in the observation files. The TSL parameter value defines whether aone particular TSL (0..7) or all TSLs ("ALL") are observed.

The SDCCH observation includes the observation reports of BSIC and BCCH ofthe serving cell.

TCH observation (TCH_OBS)

The TCH observation report contains detailed information about the seizure andrelease of TCH channel. All TCH TSLs for the current TRX of BTS aremonitored and identified in the observation files. The TSL parameter valuedefines whether a one particular TSL (0..7) or all TSLs ("ALL") are observed

The TCH observation includes the observation reports of BSIC and BCCH of theserving cell.

Incoming handover observation (INC_HO_OBS)




The incoming handover observation report contains information about one MSC-controlled incoming handover, that is, coming to the BSC. The report containsinformation about the following items:

. The new BTS and the channel

. The type and cause of handover

. Time stamps for handover requests

. The incoming handover observation includes the observation reports ofBSIC and BCCH of the target cell

Outgoing handover observation (OUT_HO_OBS)

The outgoing handover observation report contains information about one MSC-controlled outgoing handover, that is, going from the BSC. The report containsinformation about the following items:

. The old BTS and the channel

. The type, cause and result of the handover

. The location area and cell identity of target cells

. Whether the target cell belongs to the same BSC as the source cell

. The outgoing handover observation includes the observation reports ofBSIC and BCCH of both the source and the target cells

Internal handover observation (INT_HO_OBS)

The internal handover observation report contains detailed information about oneintra-BSC (that is, BSC-controlled) handover. The reports contain informationabout the following items:

. Old and new BTSs and the channel

. The type of handover

. The cause of handover

. The result of handover

. The time and duration of handover

. The location area and cell identity of target cells

. Whether the target cell belongs to the same BSC as the source cell



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The internal handover observation includes the observation reports of BSIC andBCCH of both the source and the target cells.

Clear code observation (CC_OBS)

With clear code observation the BSC Clear Codes (see BSC_CC measurement)concerning one certain cell or one certain clear code in all cells can be observed.

ISDN Abis observation (ISDN_ABIS)

With this observation the functioning of the ISDN Abis can be monitored. Theobservation record contains:

. Phase of the ISDN call (started or released)

. BTS and TRX identification

. ISDN telephone number of the TRX

. Start or release time of the ISDN call

. Release cause

BSIC and BCCH

BSIC and BCCH of the serving cells are included in observation reports asfollows:

TCH Observation

BSIC and BCCH of the serving cell

SDCCH Observation

BSIC and BCCH of the serving cell

Incoming Handover Observation

BSIC and BCCH of the target cell only

Outgoing Handover Observation

BSIC and BCCH of both the source and the target cells




Internal Handover Observation

BSIC and BCCH of both the source and the target cells


5.53 Signalling point code modification

In the current BSS implementation, if the BSS is wanted to move from MSC toanother MSC, A interface speech circuits, signalling connection control part(SCCP) and message transfer part (MTP) must first be deleted. After that all sameparts can be created with new signalling point code (SPC) of new MSC.

With this feature it is possible to change signalling point code of MSC withoutdeleting whole A-interface by using a few MML commands. After changes, MTP,SCCP and speech circuits with their old circuit identity codes are available withnew SPC of MSC. All parameters of MTP and SCCP keep their old values.


5.54 TCSM2 routine tests of A-if circuits

The TCSM2 test one verifies with very high reliability the correct operation of thespeech coding functions of digital signal processors.

During the test, the TCSM2 loops A and Ater interface timeslots in its ET2xplug-in units. After the loops are ready, the DSPs serving the channels generate atest pattern containing a base set of PCM samples into A interface direction. ThePCM samples are looped back from the ET2E and encoded with half rate speechcoding. The resulting half rate TRAU frames and located as usual into the 8 kbit/s subchannel and in case of other circuit types (16, 32, or 64 kbit/s) the half rateframes are duplicated to the other sub-channels so that the whole part of thetimeslot available is tested. The DSP decodes the returning TRAU frames andanalyses the result. If a corrupted bit pattern is detected or the comparisonbetween the sent and received frames fails, the TCSM2 raises an alarm requiringoperator actions.

The test can be started in two ways:



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. The operators start the test with the diagnostic MML when the TCSM2 intest state.

. The operator can schedule the test so that it is performed automatically toidle TCSM2 channels without disturbing busy channels. A parameterdefines how many channels (in percent) have to be free before the BSCactivates the test. Therefore, testing does not cause any unnecessarycongestion to A interface.

For more information, see BSS Transmission Management.


5.55 Transmission equipment alarm handling

This feature harmonises the Fault Code level alarm numbers of the BSC andNokia Talk-family, PrimeSite and MetroSite Base Stations in transmissionequipment alarms.

BSC supervises Nokia Transmission Equipment through the OMU's Q1 servicechannels. In addition, the BTS can supervise transmission equipment that isconnected to a local Q1 bus. The BSC only sets generic Transmission Equipmentalarms - the reason for the alarm (the fault) has to be analysed from thesupplementary information bytes. With this feature, the BAC starts to use thesame Fault Code level alarm numbers and alarm texts as the BTS (Nokia Talk-family, PrimeSite, and MetroSite) uses when a transmission equipment fault isdetected. The alarm number consists of 8000 + the Nokia Transmissionequipment fault code.

For more information, see Transmission Management in BSS.


5.56 Trace window for dropped calls

This feature provides the operator with detailed information on the last seconds ofa call after the call has been dropped unexpectedly, and thus gives the reasons forpossible problems.

The feature is implemented as an observation type Dropped Call Observation(DC_OBS). This observation collects some key parameters of the call, forexample:




. MS Power

. BS Power

. RX Level and Quality of the BS measured by the MS

. RX Level of the neighbouring cells measured by the MS

. RX Level and Quality of the MS measured by the BS

. MS Speed

. MS's distance (Timing Advance) from the BS

. Handover causes

Data on the last 16 seconds is stored in a disk file if the call drops. If the call isreleased normally, the data collected is discarded. Each call is identified with areference number. The scope of the observation is one BTS, but it can be focuseddown to one TRX to all TSLs. The observation is activated by using similarMML commands as with other observations.

The benefit of this feature is that information on real reasons for SDCCH andTCH problems can be found and the BTS with lower quality can be detected.


5.57 SCCP improvement

This feature improves the BSC A interface so that it can more easily adapt tochanges in the MSC signalling software. It consists of the SCCP State ChangeFiltering Timer and Parameter Controlled Sending of the Status Test Message(SST) features.

The SCCP State Change Filtering Timer feature makes the A interface moretolerable against short cuts in the signalling connection: only calls in signallingphase are cleared locally in case of SCCP status change to unavailable and soonafter that to available. An SCCP status change may be caused by a short PCMfailure, unit switchover, or MTP failure.

The sending of the SST status test message fastens the recovery of the signallingconnection if the signalling point restart procedure occurs, for example, due to aunit restart.




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5.58 Real time update to Base Station

The BSC sends the current time (date and time) to the Nokia MetroSite BaseStation and Nokia UltraSite EDGE BTS during the initialisation procedure. TheBase Station initialises its real time clock accordingly. The real time is alsobroadcasted to Q1 when received from BSC and used in various purposes, suchas in commissioning reports.


5.59 Runtime diagnostics and BTS alarms

Alarms generated by the Nokia MetroSite Base Station, Nokia UltraSite EDGEBase Station and Nokia InSite Base Station are reduced due to the advanceddiagnostic and alarm management.

For Nokia MetroSite BTS, only unit level and base station level alarms are sendto BSC. For Nokia UltraSite BTS, TRX level, TRE level, BTS level and BCFlevel alarms and some special alarms are sent to the BSC. For Nokia InSite BTS,only base station level alarms are sent to the BSC. Correlation rules anddiagnostic procedures ensure that an appropriate recovery procedure is activated.

The Base Station runs diagnostic tests when BTS Supervision has noticed that anobject is faulty. The Base Station reports to the BSC that diagnostics is started in acertain object. Then the BSC sets the operational state of the object to blocked.When diagnostics is ready, the Base Station requests that the BSC deblock theobject under diagnostics. The diagnostic object blocked can be a BCF, BTS, orTRX.

In order to reduce the alarms sent from the base station to the BSC, the alarmdescriptions have a variable part, which may contain text to describe the alarm inmore detail.

There are three different alarm levels and only one *** or ** alarm per object canbe active at a time:

***object faulty

**service degraded

* notification




Supervision of the Nokia MetroSite Transmission Units feature takes care of thediagnostics function for the transmission units.

For Nokia InSite Base Station, a diagnostic report is generated when a fault isdetected in a unit. The diagnostic report allows the service personnel to perform afaster and better quality repair on the faulty unit, which has been fetched from thesite. The diagnostic report is not available in the BSC or Nokia NetAct.


5.60 BTS temperature control

Nokia MetroSite EDGE Base Station

The Nokia MetroSite EDGE BTS supervises its temperature continuously byusing several sensors located in active units (in all TRXs, fan, transmission unit).The Nokia MetroSite EDGE BTS has cooling fans and heaters to providetemperature-controlling facility. Temperature control can be divided into normaland abnormal cases. The power switch-off capabilities are for abnormally hotcase.

In a normal case the MetroSite EDGE BTS SW takes care of heating and coolingin order to provide as stable operation conditions as possible. Heating and coolingis controlled gradually to ensure minimised temperature gradients and a low noiselevel.

If the Nokia MetroSite EDGE BTS starts up in an extremely cold environment,the units are heated to a normal temperature region and power supply output isinhibited.

If the temperature of a slave TRX rises too high, it gives a temperature alarm. Themaster transceiver shuts down an appropriate slave transceiver.

In addition, power supply switches the power off for all units if the unit inquestion is overheated abnormally. The power supply switches the power on afterthe unit's temperature has decreased.



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Nokia UltraSite EDGE Base Station

Nokia UltraSite EDGE Base Station monitors its temperature continuously withseveral sensors located in several BTS units (BOI, Power Supply Unit (PWSx),Dual Baseband Unit (BB2x), Transceiver Unit (TSxx), and Remote TuneCombiner (RTxx)). The BTS controls its temperature with cooling fans andheaters to provide as stable operational conditions as possible. Heating andcooling is controlled gradually depending on the ambient temperature to ensurelow temperature gradients and noise level.

If the temperature of a unit rises too high, a temperature alarm is issued. If theBOI is overheated, the BCF is blocked. If either the BB2x or the TSxx areoverheated, the associated TRXs are blocked. Power Supply Units have their owninternal shutdown and recovery in case they are overheated.

The temperature range of Nokia UltraSite EDGE BTS is -33 °C to 50 °C for theOutdoor cabinet with the optional heater, -10 °C to 50 °C for the Outdoor cabinetwithout the optional heater and -5 °C to 50 °C for the Indoor cabinets.

Cold start from extremely cold temperature

If the outdoor cabinet (with optional cabinet heater) starts up in temperature lessthan -10 °C, the control logic in the heater does not enable PWSs to switch poweron to the BTS. Instead the control logic activates the cabinet heater until thetemperature of the units reaches -5 °C. After that Power Supply units are allowedto switch on and the BOI takes over the control of heating.

Nokia InSite Base Station

The Nokia InSite Base Station has a self-cooling structure, which applies passiveventilation based on a cooling fin. Cooling without the use of a fan enables silentoperation. The Nokia InSite Base Station also supervises its temperaturecontinuously using a sensor.

In addition, the transceiver is switched off and an alarm is sent if a part overheats.The power supply switches the power on after the unit's temperature hasdecreased. To do this, the site reset signal from the BSC is needed.





5.61 Nokia Base Station resets

Nokia MetroSite EDGE Base Station

The Nokia MetroSite EDGE BTS and its units can be reset separately for testingpurposes locally via the BTS MMI (BCF, TRX) or remotely from the BSC orNokia NetAct via the Abis (BCF and TRX resets except for the transmissionunit).

The reset types are as follows:

. BCF site reset refers to a reset of the master transceiver unit and slavetransceivers

. the master transceiver unit can also be restarted without a site reset

. slave transceiver can be restarted without disturbing the master TRX

ATRX reset for the master transceiver behaves externally as a normal TRX reset,but the internal reset operation is not the same.


Nokia UltraSite EDGE BTS objects BCF, BTS and TRX can be reset separatelylocally from BTS via Nokia SiteWizard and remotely via BSC MML. TRXBaseband Units or TRX RF Units can not be reset separately; they are handled asa TRX unit. The BCF reset means a reset of all units that is, it is a site reset.

The BOI can also be restarted via Nokia SiteWizard without a site reset. ThisOMU reset restarts only BOI SW. The OMU reset is used for activating the newconfiguration file.

The TRX can also be restarted via Nokia SiteWizard. This restarts TRX SW andthus TRX HW is not reset.

It is also possible to reset and restart the Combiner Unit (RTx) with the NokiaSiteWizard.




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5.62 Autodetection of site configuration

The Nokia MetroSite Base Station and UltraSite Base Station have an ability todetect the site configuration automatically: all units, their firmware version andserial numbers and the GSM band used. Operator dependent issues like externalalarm line settings, etc. must be set by the user from the BSC or Nokia NetActsite, for example with Remote MML-session.

Nokia MetroSite Base Station

In the Nokia MetroSite Base Station, there is no HW database file to be up/downloaded. The MetroSite BTS gathers all information required from thefollowing sources: the BTS SW package, BTS configuration file, transmissionconfiguration file, autodetection procedure at the BTS, BSC configuration data,and calibration data.

A possible change in any of the information elements causes an automaticdatabase update onto non-volatile memory. The configuration is detected innormal start-up situations and in configuration changes. The latter include casesin which extra capacity ( more TRXs) is added or a faulty unit is replaced with anew one.

The plug-and-play functionality is enabled since the Nokia MetroSite system datacan be back-up copied to a slave TRX and the transmission configuration can beback-up copied to the master transceiver.


In Nokia UltraSite Base Station, this information is stored in the HW info file inthe Base Operations and Interface Unit (BOI) non-volatile memory, and it can bedisplayed in Nokia BTS Manager.

Autodetection minimises the amount of parameters that must be entered manuallyand thus reduces the chance for errors when site configuration is determined.

There are two types of autodetection procedures: full autodetection and pollingautodetection.

Full autodetection goes through the complete autodetection process for the entireBTS including: checking the existence of units, checking part and serial numbers,checking air interface synchronisation master/slave settings, checking for theexistence of MHAs, Site Support systems, etc. Full autodetection is performedduring commissioning of a new site and when there are major changes to a site'sconfiguration. Full autodetection can only be initiated via the MMI and theinformation that is autodetected is saved as a part of the system data.




Polling autodetection procedure performs constant polling of units during normalBTS operation similarly as in Nokia MetroSite BTS. This polling checks part andserial numbers of existing units and checks if new units have been installed. AfterBCF, BTS or TRX reset, units are polled and checked for any changes. If anexisting unit's part and serial numbers change, then the new information is savedto the system data file.

If units detected by full autodetection do not respond to polling, they are reportedas faulty. To detect that units have been removed, full autodetection must beinitiated.

Upgrade to an existing site

When new plug-in units are added they are detected by polling autodetectionprocedure provided that the unit supports this, that is, passive units can not bepolled (passive units are not connected to D2-, Q1- or I2C-bus). If the new unit isalready defined in the Configuration file stored in the BOI, thenautoconfiguration can be performed and the unit can be taken into useimmediately. If the Configuration file does not contain needed informationconcerning the new unit, then the unit stays in a "non-commissioned"-state. TheMMI is used to commission the new unit. Information about the new unit such asRF cable configuration, TRX logical ID, antenna cable attenuation if requiredetc., is entered. Upon this, the updated Configuration file is downloaded andsaved to the BOI and OMU reset is given to take the new Configuration file intouse. The BOI SW reset does not disturb calls being carried by the BTS.

Information about the Nokia UltraSite EDGE BTS site configuration is structuredas follows:

. All information that is autodetected is stored in as a part of the SystemData. User can not modify this information. The information sources areautodetection procedure and BSC configuration data.

. Configuration data contains information, which must be entered manuallyby the user, that is, information which can not be autodetected such as: RFcable information, TRX IDs, attenuation values for adjustable gain DualBand Duplex Units, cabinet type etc.

. Hardware Information: Part and serial number information for units, whichcan not be autodetected, is stored in as a part of the Hardware Informationdata.




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5.63 BTS supervision

The Nokia MetroSite BTS and UltraSite EDGE BTS are capable of monitoringand testing itself in an operational state without a separate command as describedbelow.

Nokia MetroSite BTS

Continuous monitoring

In Nokia MetroSite BTS, part of the monitoring is made by HW; like themonitoring of a RF-synthesizer. The following items are monitored continuously:

. internal buses of the BTS: Q1Int, D-bus, F-bus, I2C bus, cross connectionbus

. transmission units and interfaces

. RF parts: synthesizers, output power, power control, reflected power

. digital parts: processors, ASICs, interfaces

. temperature and heating or cooling system of the BTS

. power supply voltages

. reference Oven Oscillator

Mains breakdown

The mains breakdown alarm 7620 POWER LOST INDICATION can be sent tothe Abis with the help of capacitors in AC power supply. In case of a shortbreakdown that does not affect the BTS operation, the alarm is cancelled by theBTS. A typical voltage drop that lasts less than 20ms does not cause anydetectable harm to the operation.

If any of the supervision monitoring mentioned above should fail, alarm handlingverifies the alarms and makes the recovery whenever possible. For example, ifleaves, or paper gets inside the fan, the Nokia MetroSite BTS is enable to detectthat there is something preventing the fan to operate normally. So it first turns thefan off and then on, and keeps it running at the full speed for a while. If theproblem is away the operation can continue normally. But if the fan is still notworking properly, an alarm is raised and the fan is stopped.






In Nokia UltraSite EDGE BTS, part of the monitoring is made by HW, forexample, monitoring of synthesiser. Most of the monitoring procedures are soeffective that additional testing to find faulty unit is not needed. The followingitems are monitored continuously:

. internal busses of the base station

. transmission equipment interfaces

. RF parts

. Mast Head Amplifiers

. LNAs

. Nokia UltraSite Support and Nokia UltraSite EDGE BTS IntegratedBattery Backup (IBBU)

. Dual Baseband Unit (BB2x) and the digital parts of the Base Operationsand Interface Unit (BOI)

. Combining Units (RTxx, DVxx and LNAs)

. temperature (heating and cooling) system of the base station ·Power supplies: input and output voltages


If any supervision tests mentioned above fails the alarm handling is capable torun further tests in means of diagnosis.

Mains breakdown

A typical short voltage drop does not cause any detectable harm to the operationand does not cause an alarm. In case of a mains breakdown, Nokia UltraSiteEDGE Base Station cannot send an alarm to the BSC without battery backup(either integrated or external).

BTS supervision for Nokia InSite Base Station

The Nokia InSite Base Station is capable of monitoring and testing itself in anoperational state without a separate command, as described below.


Part of the monitoring, such as the monitoring of a RF-synthesiser, is done byhardware. The following items are monitored continuously:



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. internal I2C bus

. RF parts: synthesiser, Tx and Rx parts' current consumption

. digital parts: DSP, ASICs, interfaces

. heating for oscillator

. power supply voltages


If the InSite Base Station experiences an AC supply failure, the Battery BackupUnit becomes the power source. The DC level is measured and when the supplyvoltage level drops below a certain limit, the low supply voltage feed generates analarm.


5.64 Automatic picocell planning

When deploying Nokia InSite Base Stations in offices, the networkimplementation and integration must be fast and easy. The conventionalfrequency planning tools cannot usually adapt to the different planning workneeded for indoor sites and the network planners may not have the time to handlethe increased number of tasks.

Nokia has developed the Automatic Picocell Planning (APP) functionality tomeet this challenge. It is initiated with an easy-to-use tool - the Nokia InSiteWizard - for planning, commissioning, integration and verification. One personcan integrate the BTS into the network during a single visit and network planningfor signal propagation predictions, frequency allocation or selection of ahandover neighbour is avoided.

All this is made possible by:

. Frequency allocation for the Nokia InSite Base Station by scanning for andselecting an interference free frequency

. Nokia Autoconfiguration

. Coverage and performance verification

. Fully automatic detection and creation of handover neighbours

. BTS parameterisation according to the predefined indoor specificparameter sets




In addition, the Channel Finder feature is available for maintaining good qualityin the office. It responds to changes in the surrounding network, helping to reactto them before indoor quality decreases.

All the commissioning, integration and verification tasks related to theinstallation of the Nokia InSite Base Station can be performed quickly and easilyby a single portable, lightweight and inexpensive tool, the Nokia InSite Wizard.The installation engineer can perform InSite commissioning in a few minutes,includes BTS testing and autoconfiguration of Abis transmission.

To verify coverage, it is possible to set the Nokia InSite Base Station to operate asa test transmitter, even before an Abis connection is in place. Signal strengths canbe checked in different locations in the office using the Nokia InSite Wizard.

In order to find a suitable interference-free frequency channel for the newlyinstalled Nokia InSite Base Station, the installation engineer uses the Nokia InSiteWizard to scan the radio signals coming from the surrounding network and thensends the results to Nokia NetAct through the BSS network. Nokia NetActanalyses the results, selects a suitable frequency and other parameters for the newBTS, sends the parameters to the BSS network and initialises the BTS. Adjacencydefinitions are created automatically according to BTS grouping andmeasurement results. The new InSite Base Station is ready for a test callimmediately.

Nokia NetAct stores the scanning results in its database for later use. Theseresults may be complemented later by the measurement results generated by theChannel Finder, in order to cope with possible changes in the frequency plan inthe surrounding network.


5.65 Channel Finder

It is important that indoor and outdoor networks perform properly togetherbeyond the initial planning and integration phase, maintaining this performanceduring the expansion and maintenance phases. Due to the fact that the AutomaticPicocell Planning (APP) method produces a frequency plan that is separate fromthe plan for the outdoor network, a method is needed to cope with changes on oneor the other sides. Since the initial frequency allocation by the APP is done byadapting indoor GSM to the surrounding outdoor environment, the basicprinciple is to make Nokia InSite BTSs adapt themselves to external changesduring the later phases of network evolution.

There are three cases where an indoor network may require re-tuning:



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. The outdoor GSM frequency plan changes

. A new outdoor cell is introduced nearby

. Performance statistics indicate indoor quality is decreasing due tointerference

The first two cases are handled in Nokia NetAct by the Channel Finder (CF)before any conflicts between indoor and outdoor networks emerge. Nokia NetActcompares the new plan and the old plan, uses the radio measurement dataproduced by the APP and finally determines new frequency channels for indoorbase stations if necessary. The new frequencies are activated in the indoornetwork at the same time as changes take place in the outdoor network.

Naturally, the first two cases do not require any indoor vs. outdoor adaptation ifthe operator has dedicated frequency channels for indoor use only.

The last case listed above requires special attention. Nokia has developedChannel Finder for this purpose. With the help of the Channel Finder, a betterfrequency can be found for a cell suffering from external, outdoor originatedinterference.

The choice of this optimum channel is based on an analysis of signal levels fromthe surrounding cells. These measurements are provided as part of the standardGSM functionality by the MSs of ordinary subscribers while engaged in a call.The channel with least interference is found by establishing the level ofinterference for each channel used by the operator, thus enabling easy comparisonof interference levels from different cells.

When a mobile enters active mode, that is, when a call is started, the BSC informsthe MS of the BCCH frequencies that it should measure during the call. This isachieved by using the 'Double BA List' feature of the BSC. The maximumnumber of channels that can be measured at one time is 32. In addition to thelevel of the serving cell, the MS reports the six strongest BCCH channels of theneighbouring cells. The S9 software release supports a maximum of 255 differentBCCH Allocation (BA) lists per BSC. The maximum rate at which the MS is ableto report its signal level measurements is twice per second. This means thatduring a 90-second call, approximately 180 measurement reports are beingobtained and thus a measurement period of one busy hour is adequate.

The measurement results are transferred automatically to Nokia NetAct wherethey are analysed. Finally a new interference free channel is proposed for the cellunder examination.




This method can be applied to several cells simultaneously, which makes itpossible to analyse and optimise large areas during a day. The Channel FinderMeasurement can be applied regardless of the original planning method, APP ordedicated planning tool, making it feasible not only for Nokia InSite BaseStations but also for traditional indoor solutions as well as microcellularnetworks.


5.66 Nokia autoconfiguration in the Nokia GSM OfficeSolution

In addition to its other versatile and advanced properties, the NokiaAutoconfiguration and autodetection features make commissioning andintegrating the Nokia InSite GSM Base Station fast and easy. TheAutoconfiguration feature guides the user step-by-step through the wholecommissioning process. The autodetection feature finds and reports active unitsto Nokia NetAct, reducing the number of system data entries required. These newfeatures reduce the time spent at the site significantly.

The purpose of the Autoconfiguration feature is to establish a transmission linkbetween the BSC and BTS and issue the new BTS to Nokia NetAct, which thencontinues automatically by testing the BTS. If this test is successful, the BTSbecomes integrated into the network.

When the RNW object and O&M and transceiver signalling links have beencreated in the BSC and after the transmission objects related to the Nokia InSiteGSM Base Station have also been saved in the BSC, the AC pools are created inthe ET PCM. The size of the pool can be from one to 31 TSLs (ETSI) or from oneto 24 TSLs (ANSI). One or several pools can be created in the same PCM but onepool cannot be divided into two PCMs.

The pool is created as a continuous block of 64k timeslots. The BSC reserves thecircuits so that they cannot be used for other purposes without deleting the poolfirst. The BSC automatically creates and activates the access channel into the lasttimeslot of the AC pool, which is used for communications between non-commissioned base stations and the BSC. After that, the BSC is ready to serve theaccessing BTS.

The BTS to be commissioned has started the Autoconfiguration and, after it hasfound the access channel, it requests the BSC to allocate the Abis circuits for thesignalling and traffic channels. The BSC allocates the required circuits and sendsthe allocation layout to the BTS.



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The BTS start up continues with O & M signalling link activation. The BSCupdates the allocated Abis circuits to the RNW database and LapD channeldefinition files in the memory and on the hard discs. The BSC also informs NokiaNetAct about the allocated circuits.

The success of the autoconfiguration process is tested automatically. The Abisloop test is performed automatically in order to verify Abis transmissionconnections end-to-end. If the tests are passed, an indication is given to theinstaller at the BTS site, and the BSC informs Nokia NetAct.

After the Autoconfiguration process is over, each FXC E1/T1 or FXC RRI thathas a new permanent cross-connection, raises a "configuration changed" alarm.Nokia NetAct uploads the new transmission settings of the affected transmissionunits. BTS software stores a backup of the Transmission Unit's branching tableand LapD link positions to the BOI's flash memory.

The Autoconfiguration log of events is stored in the Commissioning Report whenthe configuration is performed from the configuration wizard.

For more information, see Abis Autoconfiguration.


5.67 Power system management

Power system management consists of a Power System Controller (PSC) withinthe BBU/SiSS (Battery Backup Unit / Site Support System) cabinet, which hasbeen implemented utilising the Q1 bus. The feature provides a method to controland monitor the BBU/SiSS system. The main reason for the development is toprovide network operators with more accurate information about the powersystem status, the ability to control the system remotely and to maximise theelectrical efficiency of the batteries and charging system. This enables morereliable information about the system, and also leads to fewer service visits.

The power system management is developed for ExtraTalk 2 BSS Site SupportSystem. The PSMQ1A interface unit is needed to enable the operation of thePSM. This board is incorporated inside the cabinet.

The purpose of the power system management is to:

. Store BBU/SiSS configuration information

. Collect and log BBU/SiSS data and alarms

. Send alarm signals to the BTS when required




. Perform a regular battery condition test, initiated remotely if required

. Allow Site Support System alarms, controls and logging information to beaccessed locally

. Honour existing Nokia NetAct security mechanisms

All existing BBU/SiSS features outside the scope of the power systemmanagement are preserved. PSM is basically a system where the operator canfrom Nokia NetAct manually and remotelly check the state of the BBU.

Information gained is more precise than a plain alarm indication, for example,voltage level in batteries; the operator needs to know the condition of the batteriesto this level of detail to calculate the current BB capability of the BBU.

Node Manager Access

It is possible to use the node manager software in three scenarios: At NokiaNetAct (mandatory), at the LMP of the BBU/SiSS Q1 interface card (mandatory)and remotely by a modem link to Nokia NetAct (important).

The PSMQ1A interface card is the interface unit which fits in BBUs / SiSSswhich support ExtraTalk 2. The system has a standard user interface at NokiaNetAct to manage the BBU/SiSS. The solution uses the internal Q1 bus forremote control and data transmission between Nokia NetAct-BSC-BTS-BBU.Alarms and test information is also transferred in the bus.

The PSMQ1A provides all the SiSS alarms and readings available from thecabinet's controller unit and in addition the PSM specific alarms and data.

It is possible to download new software into the PSM card/module. Provision ismade to download new software through the PSM card/module into unitscontrolled by the PSM card/module, principally the PCU or equivalent, if thePCU has the facility to be FLASH upgraded. This is applied to the currentproducts which PSM is used in and have the ability to be flashed.




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5.68 Nokia Power System Management (PSM)Enhancements

In addition to Battery Back Up/Site Support System (BBU/SiSS) respectivelyusing Q1IA adapter, a CCUA controller with Q1 interface unit is supported. Thesame management tool, PSMMan, replace all the existing management tools forcurrent Nokia BBU/SiSS and is the management tool also for all UltraSite familypower systems. This provides better information, a better user interface andcommonality of information between different types of power systems.

The battery management is upgraded to incorporate multiple test results at thenode. Customers have more access with new PSM on local mode. In local modeuser has full control to all parameters in case of default parameters need to bechanged.

Functionality of PSM has been implemented utilizing the existing Q1 bus. Ausage of PSM allows software's to be upgraded remotely into Q1IA adapter orCCUA. Software download into BBU/SiSS controller is also supported if it hasthe facility to be FLASH upgraded.

PSM consists of:

. Power systems with Q1IA (Q1 Interface unit version A) adapter

. Power systems with CCUA (Cabinet Controller Unit version A) controllerwith Q1 interface unit

. PSM Node Manager (PSMMan) software

. NMS/NetAct integration software

. Power systems using/equipped with Q1IA adapter are compatible fromBSS8 onwards and with CCUA from BSS9 onwards excluding Talk BTSsupport.

5.69 Remote BTS manager for UltraSite and MetroSite

The Base Transceiver Station (BTS) equipment can be controlled by the user viathe Nokia BTS Manager. Controlling can be done locally at the BTS site and alsoremotely via the Network Management System (Nokia NetAct).

The remote connection from the BTS Manager to the BTS via Q1 BTS ManagerRemote Connection can be done via BTS Manager application or via CommandLine Parameter.




With Remote BTS manager, the user is not able to use the following BTSManager functionality from the BTS Manager application when the BTSManager is connected remotely:

. SW loading

. BTS commissioning (Undo Commissioning)

. Abis Disable/Enable

. LMP Speed change

. BCF / Sector / TRX Block and Unblock

The user is able to start a transmission manager from the BTS Manager when theBTS Manager is remotely connected to an UltraSite or MetroSite BTS.

The user is not able to start the HW Configurator application from the BTSManager when the BTS Manager is remotely connected to an UltraSite orMetroSite BTS.

The user is only able to successfully connect to an UltraSite or MetroSite BTSrunning CX3.2 or later BTS SW. An attempt by the user to connect to any otherBTS product (2nd generation, Talk-family, PrimeSite, UltraSite or MetroSite BTSrunning earlier BTS SW, other manufacturers BTS product) should result in anerror being reported to the user.

5.70 PrimeSite TRX ID from BSC

Currently the TRX ID for the Nokia PrimeSite BTS must be set correctly to thehardware database when PrimeSite is taken into use. With this feature, PrimeSiteuses the TRX ID sent by the BSC during the initialisation. In a multi-TRXconfiguration, every PrimeSite may have a hardware database with the same TRXID.

For more information, see BCF Hardware Database Handling.




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5.71 Clock synchronisation between Nokia UltraSite andTalk-family Base Stations

The advantage of air synchronisation between several cabinets is that handoversbetween cells residing under separate BCFs (Base Control Function) are possibleto perform synchronously and that sectors in different cabinets can use commonhopping frequencies with RF hopping. This increases the channel capacity.Maximum site configuration is 9 Nokia UltraSite GSM BTS cabinets in a chainor 6 in case of combining Nokia Talk-family BTS and Nokia UltraSite EDGEBTS cabinets.

The Nokia UltraSite EDGE BTS has an external clock interface, which can beused to synchronise the air interface between Nokia UltraSite EDGE BTScabinets on site. When several Nokia UltraSite EDGE BTSs are synchronised,master BTS functions as the frame clock source to the slave BTSs. The masterBTS transmits frame clock and frame number signals to the external clock line,while the other BTSs (slaves) receive these signals. Slave BTS uses receivedframe clock signal as a reference clock signal to adjust its main frequency source.The master BTS uses reference clock signal derived from the PCM signal.

After modifications to Nokia Talk-family BTS, it is possible to synchroniseNokia UltraSite EDGE BTS to Nokia Talk BTS to serve the adjacent sectors. Inthis case the clock master is always Talk BTS because there is a permanent(approximately 50 ms) timing difference between Nokia UltraSite EDGE BTSand Talk BTSs. Only Nokia UltraSite EDGE BTS can compensate this timingdifference by delaying the internal timing.

Physical properties

The clock interface is in RS-485 format. Although the RS-485 recommendationprovides (with the 24AWG-cable) cable length up to 1,2 kilometres with 300 kHzfrequency, the total cable length in synchronisation chain is max 100 meters dueto signal delay in the cable. Also the amount of connectors (BTSs) in thesynchronisation chain affects to the total cable length due to increasedattenuation. The external clock lines have to be terminated at both ends of thechain by 120-ohm resistor adapters.

The external clock interface in the cabinet consists of two connectors: one forinput signals and one for output signals. Both input and output signals consist offrame number and frame clock parts. The clock master/slave setting in BOI isdefined via cable connections. The external clock cable connector shortcutscertain pin to ground in both input and output connector in the cabinet. Thisenables three different types of operational states:




Inputconnected

Outputconnected

Operationalstate

No Yes Master

Yes No Slave

Yes Yes Slave

No No Independent

According to the cable connection information, Nokia UltraSite EDGE BTS SWPU1 enables or disables clock signal input and output drivers in the BOI unit. Ifthe operational state is "Independent", both drivers are disabled. If the operationalstate is "Master" then clock signal output driver is enabled and input driver isdisabled. If the operational state is "Slave" then clock signal input driver isenabled and output driver is disabled.

Synchronisation recovery

In the first Nokia UltraSite EDGE BTS SW PU1 release there is no actualrecovery for synchronisation failure due to loss of BSC support (S9), forexample,. there is no information available at the BSC about which NokiaUltraSite EDGE BTSs are synchronised together. If there is a failure insynchronisation between the cabinets, slave generates an alarm and BSC thenblocks all TRXs out of service from the alarming BCF. When the faultdisappears, cancellation to the alarm is sent to the BSC, which then unblocksTRXs under that BCF object.

At start-up, Nokia UltraSite EDGE BTS reports to the BSC if it is master, slave orindependent. In the first phase BSC does not use this information but it enablesmore comprehensive recovery actions after BSC modifications (S10).

For more information, see Synchronisation.


5.72 Training Sequence Code (TSC) vs. BTS ColourCode (BCC)

Nokia BSS does not allow to define a TSC different from the BCC on the TRXsthat are not carrying broadcast or common control channels.



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According to the GSM standard 05.02, "for broadcast and common controlchannels, the TSC must be equal to the BCC."

In some configurations, to use TSC different from BCC on TCH and SDCCHchannels situated in TS0 would allow to avoid random access interference. Forexample, a random access sent on TCH on TS0 (for handover) could be detectedas valid on the RACH. Apparently, this could happen when frequency channels inuse in the TS0 in non-BCCH TRX are quite close to BCCH frequency channel(400 kHz or 600 kHz spacing).

This feature removes the TRX specific constraint: TSC = BCC. Exception for thislimitation is BCCH and PBCCH TRXs and also Base Band hopping cell (or Baseband hopping layer in IUO case).

This would lead to following network quality improvements:

. less ghost CHANNEL REQUEST on RACH => better SDCCH efficiency

. less misbehavior on TS 0 during handovers





6 Transmission

The features and functionalities presented in the following sections are related tothe transmission in the Nokia BSS.


6.1 Trunk network maintenance

Functional disturbances in the trunk network are inconvenient to the customersusing the network and cause financial losses to the operator. Therefore, it isimportant that the exchange can adapt itself even to very serious malfunctions ofthe trunk network and provide reliable service with the available resources. Inaddition, the system supports fault-preventive and corrective operations.

The DX 200 system provides real time supervision of the trunk network. Thetrunk network and the exchange terminals are the objects of the supervision. If adisturbance occurs, the system isolates the faulty connection from traffic until theconnection is back in order. The maintenance personnel are informed of thesituation through the alarm system and new traffic is routed to the correctlyworking connections.

The DX 200 system is able to provide high-quality trunk service even insituations where the disturbances are very serious. In many cases it is possible topredict the faults appearing in a trunk circuit days in advance, based on anincreasing number of short disturbances. For this purpose, the system recordsdaily statistics about the disturbances and the availability characteristics of alltrunk circuits. Repair work is supported by performing short measurements ondisturbance characteristics found in the trunk circuits. The measurements arecontrolled with the MML commands.

For more information, see, Trunk Network Maintenance.




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6.2 Ater trunk transmission allocation

The most favourable position for the Transcoder is on the MSC site because 16kbit/s subchannels are used on all transmission links between the BTS and MSCsite and submultiplexing can be used to save transmission links.

TCSM1

First generation transcoder/submultiplexer. The maximum number of full ratechannels is 90. For more details, see Nokia BSS Transmission Configuration.

TCSM2E

Second generation transcoder/submultiplexer. Together with half rate-relatedrouting and switching in the BSC and the TCSM2 it is possible to optimiseutilisation of Ater PCM lines. In full rate-only configuration the maximumamount of Ater channels is 120 with GSWB. In half rate-only configuration themaximum number of Ater channels is 210 with GSWB. It is also possible to havemixed configurations with the accuracy of one A-interface PCM, e.g. 2 full rateA-interface PCMs and 3 half rate A-if PCMs carried over one Ater PCM link,totalling 150 traffic channel in this example with GSWB. For more details, seeTCSM2 Functionalities and Nokia BSS Transmission Configuration.


6.3 Redundant Ater (or A) trunk

If a failure in the transmission connection occurs between the BSC and TC (MSCin case of A interface) sites, an alternative transmission route (redundancy) isdesirable. In such a case a duplicated point to point type connection provides therequired protection. This feature is implemented by using standard the G.703 2Mbit/s PCM frame structure. For more details, see Nokia BSS TransmissionConfiguration.


6.4 Abis trunk signalling

Radio signalling link is a logical link between the BSC and the BTS in Layer 2.RSL is identified by a functional address known as Service Access Point,SAPI=0. The Radio signalling links over the Abis interface are addressed todifferent units by Terminal Endpoint Identifiers, TEI. TEI values are fixed andcorrespond to the TRX-id. TEI management is not used. One signalling channel




is used for each transceiver (TRX) and one for each BTS base control function(BCF/OMU). Alternative signalling speeds are available: 16 kbit/s, 32 kbit/s or64 kbit/s. The selection of the signalling speed is done in the commissioningphase on BTS basis. The same selection is also done on the BSC site whenchannel configuration is defined. Normally 16 kbit/s TRX signalling speed isrecommended for FR operation. 32 kbit/s TRX signalling rate is recommendedfor HR use. At the BCF/OMU signalling rate of 64 kbit/s, the SW downloadingtime needed is approximately four times shorter than with 16 kbit/s signalling.


6.5 Redundant Abis trunk

If a failure or problem in the transmission connection occurs between BSC andBTS sites an alternative transmission route (redundancy) is desirable. Twoalternative strategies are available for redundancy. The first is a duplicated point-to-point type connection, and the second is a redundant multidrop loopconnection. These two alternatives provide solutions for different transmissionneeds: either the traditional redundant point-to-point configuration or theeconomical multidrop loop configuration. This feature is implemented by usingthe standard G.703 2 Mbit/s PCM frame structure. For more details see NokiaBSS Transmission Configuration.


6.6 ISDN Abis (ETSI)

ISDN is an alternative for Abis transmission. It may be attractive because oftransmission tariff or lead-time reasons. The implementation of ISDN connectionin the BTS transmission unit (TRU) can include a fixed 2 Mbit/s (or 64 kbit/s)PCM interface and two ISDN 2B+D interfaces. Interface between BSC and theISDN network is based on ETS 300-102. Connection between BSC and BTShave to be unrestricted digital 2 * 64 kbit/s.




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6.7 Abis transmission by HDSL

HDSL (High bit rate Digital Subscriber Line) is a transmission interface using 2-or 4-wire twisted pair copper connections in the Abis interface. Two HDSLmodems are integrated in the BTS's transmission unit, TRU. There is also one 2MPCM interface in this HDSL version of TRU. The maximum speed of the HDSLmodem is 2Mbit/s. Smaller speeds (1Mbit/s, 512 kbit/s) can be used if fulltransmission capacity is not required. Smaller speeds can also be used to extendthe range of operation. The lower the speed, the longer the distance of copper linecan be. A typical transmission distance can be 5 km with 2Mbit/s speed. This is,however, highly dependent on the type of wire used.

The benefit in using HDSL modems is that normal telephone lines can be usedefficiently for BSS transmission. There is, however, a restriction that a galvaniccontact is needed between modems. In practice this may result in a combinationof HDSL and PCM lines in Abis transmission.


6.8 Satellite Abis

This feature enables the operator to create coverage of the network in areas wherethe coverage could not be otherwise implemented due to the limitation oftransmission media. Only a minimum number of equipment is required at theremote cells. The feature can be utilised either on Abis or Ater interface. Tosupport satellite BSC-BTS circuits, this feature enables a connection of BTSs to aBSC over a transmission path having long delay (about 280 ms in one direction).BSC and BTS parameters and timers are adapted for long delay.

Time alignment procedure between TCSM1 and BTS is modified by usingdifferent proms in TCSM1. In TCSM2 the time alignment can be turned off fromthe command menu. This feature is activated by enabling the parameter on/off perthe BSC. Because of the fixed MS timers there may be re-attempts in thesignalling, causing limitations to the capacity of these cells.





6.9 Abis trunk transmission allocation

Up to four FR/EFR speech channels (or up to eight HR speech channels) aremultiplexed on a single PCM timeslot. Point-to-point star, multidrop chain orremote star transmission connections could be created between BSC and BTSsites. By this flexibility all kind of transmission needs can be satisfied: traditionalstar configuration, economical multidrop chains and reliable multidrop loops areall possible. Up to 12 TRXs are supported on a single 2 Mbit/s PCM line.Accepting that one or two speech channels are lost, up to 15 TRXs could besupported. This feature is implemented using the standard G.703 2 Mbit/s PCMframe structure. For more details see Nokia BSS Transmission Configuration.


6.10 T1 Abis (ANSI) BTS

The T1 TRU supports ESF (Extended Super Frame) and SF/D4 framing. ESFsupports CRC-6 checks and 4 kbit/s datalink for performance management.


6.11 TRU manager

Nokia Talk-family and Nokia PrimeSite BTSs include a transmission unit calledTRUx. This unit handles the PCM Abis interface. It comprises of 3 pcs 2 Mbit/sinterfaces as well as 2 Mbit and 8 kbit cross connection fields. The timeslotallocations of the 2 Mbit/s interfaces and the configuration on cross connectionfields have to be defined before the BTS can establish an Abis connection to theBSC. The standard way to do this definition is by using a separate ServiceTerminal or Macro Service Terminal Emulator. TRU manager is a Windowsbased software which makes it possible to do the above mentioned transmissionunit configurations in a user-friendly way. The TRU manager is connected to theTRU card's connector in the BTS.





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6.12 Supervision of transmission equipment

The DX 200 Base Station Controller (BSC) system provides real time supervisionof transmission equipment including the transcoder unit, submultiplexer, dynamicnode, supervisory substation, base band modem and digital microwave radio link.

Other transmission equipment, for example optical line equipment, can besupervised by common name Transmission Equipment (TE). The transmissionequipment at a BTS site - the Base Station Interface Equipment and theTransmission Unit - are supervised by the Base Transceiver Station itself.Depending on the configuration, the digital microwave radio links and BasebandModems (BBM) can be supervised either by the BTS or the BSC.

The operation principle of the supervision is a master-slave system based onpolling. "Polling" commands are transferred from the master to the transmissionequipment. If the status of the polled equipment is not acceptable, a longerdialogue is started. The master obtains more detailed information on the faultsituation, sets the appropriate alarm and, if necessary (in Transcoder faults),blocks the faulty circuit. The alarms are printed locally and transferred to theOperation and Maintenance Centre (Nokia NetAct) through the Operation andMaintenance (O&M) network.

Supervision of transmission units by other manufacturers ( Nokia MetroSite)

If non-Nokia transmission equipment is supervised via External Alarm andControl (EAC) lines, alarms can be sent to two possible destinations: either theBSC and Nokia NetAct or Nokia NetAct . In the first case, supervision isperformed by the master TRX and alarms are reported as normal external alarms.In the latter case, supervision is performed by Nokia NetAct and the master TRXdirects the alarm to the transmission unit as the EAC lines become active. Duringthe next poll request of Nokia NetAct , the alarm isreported as a transmission unitalarm.

The functionality described above is implemented by defining a new parameterfor each external alarm. The parameter defines whether the alarm is reported as anormal external alarm or conducted to a transmission alarm.





6.13 Q1 interface between the BSC and transmissionequipment

With the Q1 Interface Handling MML, the user creates the service channels usedin communication between the BSC and the transmission equipment. The Q1service channels are asynchronous serial communications channels. The protocolused is Nokia's own Transmission Management System Protocols. The defaultmaximum number of Q1 service channels in the BSC is 18. The user also definesthe supervised equipment. Altogether 512 pieces of equipment can be definedinto Q1 service channels under the BSC All the equipment in the same channelhas a unique address (polling address). To open the service channels, thetransmission equipment has to be configured locally with a hand-held serviceterminal or with the Node Manager Program.



6.14 Wired alarm collection at transmission equipmentsite

The Supervisory Substation can be installed to for example, DN2 rack. It offers32 E&M or TTL inputs. The BSC supervises the SSS with own polling address.The user can define a wire specific text. It is printed out locally and transferred toNokia NetAct in the SUPERVISORY SUBSTATION ALARM's operationsinstructions field.



6.15 Remote use of node managers of Nokia NetAct atNokia NetAct site

This feature enables the remote management of the Nokia transmissionequipment from Nokia NetAct site. The management is done by means of NokiaNetAct , which is a Windows based product providing a common platform toexisting and future Node Manager. Each Node Manager is dedicated to one type



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of a transmission node, for example, DN2, DB2 or DMR. In GSM 900/1800networks Nokia NetAct is primarily meant for the configuration managementsince the fault management (transmission alarms) is handled via the DX200 orBTS alarm systems.

The remote transmission node management is based on a transparent Q1 channelfrom Nokia NetAct to a transmission node: a separate PC containing NokiaNetAct software and Node Managers is connected with the TCP/IP interface toNokia NetAct, which converts the data stream to the NetAct -BSC interface. Onthe BSC- NetAct interface the existing OSI connection is used, thus no additionaltransmission capacity is required. The BSC converts the information into a properQ1 bus or Abis O&M link. In the latter case the transmission node exists at theBTS site.



6.16 Remote transmission equipment management

Service terminal emulator MML in BSC

A Man Machine Language (MML) program is implemented for performingconfiguration management and performance management operations (and somebasic fault management operations) for the BSS transmission equipment remotelyfrom the BSC site. The BSS transmission equipment handling MML emulates thefunctions of the hand-held service terminal. When the equipment is located at aBTS site, the management commands between the BSC and BTS are sent via theLAPD-based O&M link. The BTS OMU forwards the commands to the managedequipment via the local Q1 bus. The MML session can be used remotely fromNokia NetAct for centralised control of the transmission equipment in thenetwork. One session can be active at a time. Feature Q1 Supervision DuringRemote Session allows simultaneous remote session and collection of statisticswithout discontinuing alarm polling.





6.17 Local transmission equipment management

Hand-held service terminal

A hand-held service terminal is a small terminal with LCD readout and akeyboard. It is designed for managing transmission equipment in field conditions.The hand held service terminal provides basic functions for managingtransmission equipment, such as:

. review of alarm status in the equipment

. review the firmware and hardware identifications

. controls (loops etc.) and permanent parameter settings

. review of measurements and statistics

The initial settings of different transmission units can be performed with theService Terminal. Also copying of settings from one unit to another is possible.

Macro service terminal emulator software

The Macro Service Terminal Emulator (MSTE) is a PC based software which isused to install and configure transmission equipment. The Macro STE providesthe same functions as the hand-held Service Terminal. The Macro STE providesa macro builder facility, which means that it has the possibility to record theexecuted menu command paths and save them on a file. The saved menucommand files can be executed later as "macro commands". The Macro STEprogram runs on a PC under the MS Windows operating environment. Whenused Macro STE application PC serial port with RS232/RS485 converter moduleis connected to the Transmission Equipment service interface.

Node manager softwares

The Node managers run also on a PC under the MS Windows operatingenvironment. Each Node Manager is dedicated to one type of a transmissionnode, for example, DN2, DB2 or DMR. With the node manager the user can forexample build cross connection tables in a user-friendly way through graphicalinterface.




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6.18 Nokia GSM Office transmission operability

This feature implements the operability of the Nokia InSite Base Station, NokiaInHub and FIU 19. The indoor transmission equipment is managed by an internalNokia standard for the management of PDH equipment, known as Nokia Q1.

Every transmission unit provides alarm statistics.

The Nokia GSM Office Transmission Operability feature consists of two sub-features:

. Nokia GSM Office Transmission Equipment Support provides support fortransmission units, including alarm handling

. Nokia GSM Office Transmission Equipment Statistics, with measurementtypes specific to Nokia GSM Office as an enhancement to existingfeatures.

The Nokia GSM Office Transmission Equipment Support performs the followingtasks:

. fault management for Nokia Q1-implemented equipment

. transmission alarm harmonisation

. Nokia InSite Base Station transmission equipment handling

. check sum polling for Nokia Q1-implemented equipment

The Nokia GSM Office Transmission Equipment Statistics offers information onthe signal quality of the Nokia InSite Transmission system.

In S9, the Nokia InSite Base Station based picocellular solutions allow a greaternumber of base stations and related transmission equipment. In practice, thismeans a large set of counters and therefore the operator has the ability to measurethe Nokia InSite Base Station transmission equipment in two ways:

1. All equipment can be measured with a 24-hour period. This measurementgives a fixed set of counters, which are near-end G.826 signal qualitycounters:

. total time

. available time

. errored seconds


. background block errors

. errored block




2. A certain set of Nokia InSite Base Station transmission equipment can bedefined. The Nokia InSite Base Station transmission equipment refers toeither the whole equipment or part of it (functional entity and supervisionblock). It is also possible to define the counters that are collected from theequipment. To do this, the operator has to know the topology of thetransmission network so that the measurement subject can be chosen.


6.19 Supervision of Nokia GSM Office transmissionunits

The Nokia InSite Base Station supervises its transmission functionality. Alarmsgenerated by the Nokia InSite Base Station are transmitted to the BSC, whichfurther transfers them to Nokia NetAct.

The BSC controls the Nokia InHub, FIU 19 and microwave radio transmissionusing the Q1 bus.


6.20 Support for Nokia microwave radio links

This feature allows to connect up to 26 external radio links into the internal Q1bus of Nokia Talk-family BTSs. Services provided for radio links are alarmpolling & forwarding to the BSC and remote service terminal access. Theseservices are equal to the ones currently available for Nokia 2nd generation BTStransmission unit (BIE).

Note

Nokia Talk-family BTSs already include (available in D1.0) similar support forit's transmission units (TRUx and integrated radio links). The number oftransmission units supported is currently 8 and this will be increased by 26 linksto create a total of 34 transmission equipment per BTS.





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6.21 Transmission operability

The feature implements the operability of the Nokia UltraSite transmissionequipment.

The Nokia UltraSite transmission equipment is managed by an internal standardwithin Nokia for the management of PDH equipment called Nokia Q1.

The Transmission Operability provides support for transmission units in theNokia UltraSite Solution and measurement types specific to Nokia UltraSite.

Support for transmission units includes the following tasks:

. fault management for Nokia Q1-implemented equipment

. transmission alarm harmonisation

. Nokia transmission equipment handling

. configuration change detection from Nokia Q1-implemented equipment

Statistics part of the feature offers information on the signal quality of the NokiaUltraSite transmission system.

In S6 and S7, it was possible to measure transmission equipment as whole groups(DMR, DN2, TRU). So each measurement directed to a certain group gives thecounters from all the equipment in the network.

In S8 the Nokia MetroSite Solution allowed greater number of base stations andrelated transmission equipment than in earlier releases. The BSS9 functionalitywith Nokia UltraSite GSM BTS is the same. In practice, this means a large set ofcounters and thus operator has the possibility to measure the transmissionequipment in two ways:

1. Firstly, all equipment can be measured with a 24-hour period. Thismeasurement gives fixed set of counters, which are near-end G.826 signalquality counters:

. total time

. available time

. errored seconds


. background block errors

. errored block




2. Secondly, a certain set of transmission equipment can be defined. Themeasurement interval can be 15, 30 minutes, 1,2,3 or 24-hour.Transmission equipment refers to either the whole equipment or part of it(functional entity and supervision block). To be able to do this operator hasto know the topology of the transmission network so that he is able tochoose the measurement subject.



6.22 Supervision of transmission units

The Nokia UltraSite EDGE BTS supervises the transmission equipment, whichcan be internal or external. Alarms generated by transmission units aretransmitted to the BSC, which further transfers them to Nokia NetAct.

The operation principle of supervision is a master-slave system based on polling.The polling commands from the BOI to the equipment are transferred through theQ1 service channel. If the status of the polled equipment is not acceptable, alonger dialogue is started. The BOI obtains more detailed information on the faultsituation and sets or clears the appropriate alarm.

In the latter case BTS supervises the operation of transmission units in a similarway as any other BTS unit is being supervised. Alarms are forwarded towardsBSC as they are generated.

Supervision of other manufacturers transmission units

If non-Nokia transmission equipment is supervised via External Alarm andControl (EAC) lines, alarms can be sent to two possible destinations: either theBSC and Nokia NetAct. In the first case, supervision is performed by the BOI andalarms are reported as normal external alarms.

In the latter case, supervision is performed by Nokia NetAct and the BOI directsthe alarm to the transmission unit, as the EAC lines become active. During thenext poll request of Nokia NetAct., the alarm is reported as a transmission unitalarm.

Functionality described above is implemented by defining a parameter for eachexternal alarm. The parameter defines whether the alarm is reported as normalexternal alarm or as transmission alarm.




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6.23 Synchronisation

General

In normal network conditions, synchronisation information is carried byselected 2.048 Mbit paths from upper to lower hierarchical levels according to thesynchronisation plan, from the MSC down to the BTSs. The synchronisationunits are used in master-slave network hierarchy or they can run plesiochronouslyif synchronisation information has been lost.

BSC

BSC synchronisation unit selects the signal, which has the highest priority froma group of pre-selected digital paths as the active synchronisation signal.Changeover of the synchronisation signal can be done using MML commands. Itis automatic in case of input failure. The synchronisation unit is duplicated.Changeover between an active and a spare unit can be done by using MMLcommands and is automatic in case of failure. The changeover functions are allcontrolled and cause no disturbance in traffic or signal quality.

TC

The Transcoder is able to use one PCM of a predefined set of PCM inputs as thesynchronisation sources. Selection method is automatic.

BTS

Each BTS synchronises to the incoming 2MBit signal via its PCM interface. Thisway it is ensured that the whole transmission bit stream path TC->BSC->BTS isfully synchronised.

For more information, see Synchronisation.





6.24 Duplicated transmission card

It is possible to fit into the Nokia Talk-family BTS a second, optionaltransmission card (TRU) to expand the possible number of PCM transmissionlinks from 3x2 Mbit/s to 4x2 Mbit/s. This makes it possible to use BTS as atransmission network node, because standard TRU has also an internal cross-connection field.

Note

This option is not available with the Nokia Flexitalk BTS.


6.25 Combined O&M and telecom signalling

This feature means that O & M (OMUSIG) and telecom signalling (TRXSIG)links can be placed on the same timeslot on Abis PCM. The combining of the O& M and Telecom signalling enables more efficient use of transmission capacity.

The transceiver of the Nokia MetroSite BTS can be configured as a master orslave of a TRX. The master transceiver takes care of both telecom and O & Mfunctions. So combining of O & M and Telecom signalling is easier to carry out.

Note

In the first SW release TRX 1 is the master TRX.

Combination of links does not affect the current procedures inside the BSC, sincethey are seen as two separate logical links. Both combined links have their ownD-Channel number in the BSC. The states of the links are handled independently.Links have own SAPI and TEI values and polling.

LAPD connectiontype

SAPI TEI Supported bit rates

TRXSIG 0 TRX-id 16, 32, 64



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LAPD connectiontype

SAPI TEI Supported bit rates

Autoconfigurationaccess channel

61 0 64

OMUSIG 62 1 16, 32, 64

Combined OMUSIG andTRXSIG *)

0 and 62 are used:0 forTRXSIG,62 for OMUSIG

TRX-id and 1 are used 16, 32, 64

L2 control 63

*1) Two LAPD connection types use the same position on Abis PCM


6.26 Ater trunk transmission allocation

TCSM2A

This feature is dealing with the second generation transcoder/submultiplexer.Together with half rate-related routing and switching in the BSC and the TCSM2it is possible to optimise utilisation of Ater PCM lines. In full rate-onlyconfiguration the maximum amount of Ater channels is 96. Half rate is notcurrently available in 1.5 Mbit/s PCM environment.





7 Services

The features and functionalities presented in the following sections are related tothe Nokia BSS services.


7.1 Tandem Free Operation (TFO)

The speech quality of GSM is of great importance to operators. Quality isessential in gaining competitive advantage.

In the GSM network, a tandem connection is created in an MS to MS call as inthis case, as two TRAUs (Transcoding and Rate Adaptation Units) makeunnecessary decoding and encoding in the network.

The number of MSs, as well as the number of MS to MS calls, has increasedrapidly and the half rate coding with weaker tandeming properties has beenintroduced to the networks. This results in the degradation in speech quality ofthese calls becoming more noticeable to the end users.

Improving the quality of MS to MS calls is standardised in ETSI and the workitem is called Tandem Free Operation (TFO) of Speech Codecs.

The primary objective of TFO is to improve the speech quality in MS to MS callsby avoiding double transcoding. By using TFO, speech is transported in itscompressed form across the network(s), which minimises the number oftranscodings that are done.

Subjective tests performed by ETSI show significant gain in the subjectivequality for all speech codecs (FR, EFR, and HR).

Tandem free should apply to MS to MS calls independently, regardless ofwhether the MSs are located within the same PLMN network or in differentnetworks. Tandem free can be established if the same speech codec, for example,EFR , is used on both sides. It therefore applies to all existing codecs (FR, HR,and EFR) if the same codec is used on both sides.



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The establishment phase and the in-band signalling required

When a call is started, there are several things that are not known to the system,although they are essential in order to decide whether TFO should be applied ornot. First of all, the call should naturally be an MS to MS call if TFO is to beapplied. Furthermore, both transcoders involved should be TFO capable and thesame codec should be used on both sides. In addition, the connection between thetwo transcoders should be transparent.

Therefore an establishment protocol takes place between the two transcoders inorder to verify these issues. This happens before switching to the TFO mode,while still transmitting the normal PCM speech between the two transcoders. Theestablishment phase hence requires an in-band-signalling channel obtained byperforming some bit-stealing on the PCM speech. The bit-stealing is performed insuch a way that the degradation of the speech is inaudible; establishing TFO isattempted on all calls whether MS to MS or MS to fixed phone.

The signalling channel is obtained by stealing the least significant bit of every16th PCM sample with a pseudo-random pattern. This guarantees that thesignalling cannot be heard.

TFO mode

In the TFO mode, the compressed speech is transmitted in a format close to theTRAU frame used today in the Abis interface. The format is called the TFOspeech frame and requires one or two bits per PCM sample depending on the typeof codec (HR for the one-bit case and FR and EFR for the two-bit case). Thecompressed speech is mapped onto the 2 LSB (Least Significant Bit) of eachPCM sample or the LSB depending on the number of bits required. Thereforethere is always some PCM speech information available in the upper bits. Thecodec negotiation mechanism is not implemented and TFO operation starts only,if both codecs used by the BSS are identical.

The handling of equipment that could violate the transparency of the TFO linkbetween TRAUs, for example, stand-alone acoustic echo cancellers, is alsostandardised. In other words, the manufacturers of this equipment can update it tosupport TFO transparency. This equipment is called In Path Equipment (IPE). IfIPEs are not updated the TFO transparency should be guaranteed by transmissionplanning in order to make TFO possible.

It is possible to implement TFO by changing only the transcoder software andthere are no modifications to other network elements. The feature supports all theprevious functions of the network and prevents tandem coding in all the MS toMS calls when the speech codecs at both ends are the same, thus improving the




speech quality. The only requirements are an end-to-end digital connection andTRAUs that support the method. A non-digital connection or non-compatibleTRAU results only in a normal-quality call as the tandem prevention methodcannot be used.

Note

TRAU features that use PCM coded speech cannot be used during TFO calls.These features are Acoustic Echo Cancellation (AEC), Noise Cancellation, FixedGain and Adaptive Gain.

For more information on TFO, see TCSM2 Functionalities.


7.2 Noise Suppression

The majority of MSs are used in urban environments. This makes backgroundnoise an important factor in the final voice quality perceived by the end user. Ahigh background noise level and low signal-to-noise ratio (SNR) can degradevoice quality so much that the listener becomes annoyed or concentrates onbackground sounds rather than speech. In very low SNR conditions, even theintelligibility of the conversation might suffer.

One way to improve customer satisfaction and to reduce churn, is to improve thesignal-to-noise ratio of calls. By using Nokia Noise Suppression (NS),implemented in the TCSM2, the SNR is effectively increased by lowering thenoise level without attenuation of the speech signal.

Nokia NS is compatible with all existing GSM speech codecs (FR/HR/EFR) andcan be activated individually for each codec on the A-interface timeslot or PCMcircuit basis. Furthermore, the Nokia NS can be used either on the uplink ordownlink, or it can be active in both directions. The level of Noise Suppressioncan be adjusted by the MML. As Nokia NS is only an additional feature in theTCSM2 software, no hardware or firmware upgrades are needed to make use ofthis feature.

The Nokia Noise Suppression is a state-of-the-art quality solution which providesexcellent voice quality by removing the background noise and is compatible withall FR/EFR/HR codecs and AEC feature. With this solution it is possible toincrease end-user satisfaction.



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For more information, see TCSM2 Functionalities .


7.3 Support for Noise Suppression (NS) and Dual RateCodec (DR) in the same pool

With this enhancement, it is possible to allow NS and DR configured in the sameTCSM circuit pool on A interface.

The possible combination of circuit pools:

Supported codecs and features Supported A-interface pools

FR, HR, EFR, AEC, HSCSD, NS 3, 7, 10, 13, 20, 21, 22 (DR, EFR & DR, HS2, HS4,EFR & DR & D144, HS2 & D144, HS4 & D144)

FR, EFR, AEC, TFO, NS 1, 5 (FR, EFR & FR)

HR, AEC, TFO, NS 2 (HR)

AMR, AEC, NS 23 (AMR)

FR, HR, EFR, AEC, HSCSD, TTY 3, 7, 10, 13, 20, 21, 22 (DR, EFR & DR, HS2, HS4,EFR & DR & D144, HS2 & D144, HS4 & D144)

FR, EFR, AEC, TFO, TTY 1, 5 (FR, EFR & FR)

AMR, AEC, TTY 23 (AMR)

7.4 Queuing

Queuing is a method for improving service level of subscribers in case oftemporary congestion. The operator can define the maximum queuing time andthe length of the queue per cell. Three different kinds of queue types areintroduced; one of the queue types handles call setups, another one non-urgentHOs and the third one urgent HOs. The operator can make a prioritisationbetween these three queue types.

For more information, see Radio Resource Pre-emption and Queueing in BSC.





7.5 Queuing and priority

Queuing and Priority is a feature designed to offer guaranteed level of service forsome subscribers. Each subscriber can be associated with priority information,which defines following things:

. priority level (0-14)

. queuing indicator (Queuing allowed / not allowed)

. pre-emption capability (Pre-emption allowed / not allowed)

. pre-emption vulnerability (Pre-emption vulnerable / not vulnerable)

Queuing

Queuing is a method for improving the service level of subscribers in case oftemporary congestion. If the priority information of the subscriber identifies thatqueuing is allowed, but pre-emption capability is not, the subscriber is put to thequeue to wait if they can be served after a moment. The queue is sorted accordingto the priority level of subscribers. The operator can define the maximum queuingtime and the length of the queue per cell. Three different kinds of queue types areintroduced; one of the queue types handles call setups, another one non-urgentHOs and the third one urgent HOs. The operator can make a prioritisationbetween these three queueing types.

Forced handover

Forced Handover is a method for improving the service level of importantsubscribers while maintaining the service level of normal customers in case oftemporary congestion. If the priority information of the subscriber identifies thatpre-emption capability is allowed and the priority level of the subscriber isbetween 2 and 14, the forced handover may occur for the call (pre-emptionvulnerable) already in progress in the cell. Released resource is assigned forhigher priority subscriber.

Forced release

Forced Release is a method for ensuring the service level of very importantsubscriber in case of congestion. If the priority information of the subscriberidentifies that pre-emption capability is allowed and the priority level of thesubscriber is 1, the forced release occurs for the call (pre-emption vulnerable)already in progress in the cell. Released resource is assigned for the higherpriority subscriber.

For more information, see Radio Resource Pre-emption and Queueing in BSC.




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7.6 Acoustic Echo Cancellation (AEC)

On the MS (Mobile Station) side, the voice coming from the earpiece of the MSis picked up by the microphone, that is, there is an acoustic echo travelling by airand along the body of the MS. The GSM recommendation 3.50 states that ahandset and a hands-free MS should perform acoustic echo cancellation. In otherwords, the MS should have a built-in echo suppresser or canceller and no acousticecho cancellation should be needed on the network side. However, it seems thatsome MSs are not capable of removing the acoustic echo sufficiently and thesubscriber may sometimes hear the mobile originated echo. In an MS-to-PSTNcall this means that the PSTN subscriber hears his/her own voice as an echo witha delay of about 200 ms, if the echo cancellation in the MS is not successful. Thesame problem exists also in MS-to-MS calls although in these cases the delay isnaturally about 400 ms. In these cases, the echo cancellation should be done bythe built-in echo canceller of the MS, as the normal echo cancellation in the MSCdoes not perform any echo cancellation in the uplink direction.

Because of the reasons explained above, an Acoustic Echo Cancellation feature isincluded into the TRAU software. Nokia AEC operates with all three GSMspeech codecs (FR, HR and EFR) and the uplink DTX state is no longer berelevant to proper operation. Another improvement in AEC is the possibility tocompensate long fixed transmission delays by giving a command from the userinterface to adjust the AEC window to the known additional delay (0-620 ms) in20 ms steps. The AEC support for each codec can be switched on/off andadditional delay can be controlled by the transcoder MML. Note: AEC for HRand EFR is not available for TCSM (TCSM2 required)

Note

The S7 version of the Nokia AEC for FR is slightly different from the S6 version,because the uplink VAD and comfort noise generation in the TRAU are the samefor all codecs in case AEC is used, but both the AEC operation and performanceare practically unchanged. The uplink DTX is no longer relevant to the AECoperation.

Note

The additional delay improvement feature can be used to handle delay caused bywhatever transmission equipment (satellite connections are one example) in AECoperation.

For more information, see TCSM2 Functionalities.





7.7 IDR and TR as per PIE (Priority InformationElement)

The BSC can classify mobile subscribers (MS) in two classes: Micro cellularNetwork (MCN) subscribers and GSM subscribers. Initially the subscriber typeswere distinguished with the help of the MS power class. An alternative methodfor distinguishing between the subscriber types is the use of Priority InfoElement (PIE). The new subscriber class can be defined in addition to the GSMand MCN subscriber classes by using this PIE information: priority subscriber.The MSC determinates the type of the subscriber and sends the correspondingPIE to the BSC in the Assignment Request and Handover Request messages.


7.8 Trunk reservation

The Trunk Reservation is designed to allow the shared use of the resources of theradio network for different types of subscribers (GSM, MCN, and PRIORITY).The coverage area of a cellular network system can be divided into differentservice areas, each cell of the network belonging to at least one of them. Forinstance, the network system can be composed of the GSM network with theMCN as a subservice area. The decision whether a subscriber is served in a cell isbased on the service areas that the cell represents, as well as on subscriber-specific restrictions.

The trunk reservation procedure is used for discriminating the grade of thedifferent services of a cell joined to several service areas. On the basis of a cellshared by several services different kinds of traffic types (for example, type 1 =GSM, 2 = MCN, etc.) are defined for a cell. A decision threshold is defined as afunction of the number of currently free radio resources, that is, idle trafficchannels and service types. When the trunk reservation algorithm is applied, arandom variable R is tested against the applicable threshold to find out whether afree traffic channel is available for the specific traffic type. The random value R isuniformly distributed between 0 and the maximum value M and regenerated foreach request. Possible values (Xij) of the threshold can be presented as a table:



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Idle TCHs Traffic type 1 Traffic type 2 . . . Traffic type j

1 X11 X12 . . . X1j

2 X21 X22 . . . X2j

3 X31 X32 . . . X3j

. . . . . . . . . . . . . . . .

I Xi1 Xi2 . . . Xij

Access is granted only if R < Xij, with i and j corresponding to the number offree channels and traffic type respectively. Access can therefore be rejected eventhough there are idle channels left. If more than j channels are free, all accessattempts are granted.

Two alternative reservation methods are available for PRIORITY subscribers:static and dynamic reservation of channels. In static reservation, once the prioritychannels have been allocated to priority subscriber type users, the remainingspare channels are available to any user. Thus, in static reservation the parametervalue L tells the number of simultaneous priority calls, which the BTS has to beable to transmit. In dynamic reservation the parameter value L tells the number ofthe channel that has to be left available to the priority subscriber type subscribersonly, no matter how many ongoing priority calls there are in the BTS. Theselection between static and dynamic reservation of channels is made on a per cellbasis.

For more information, see Trunk Reservation.


7.9 Intelligent Directed Retry

Intelligent Directed Retry feature works in a similar way to the Directed Retryfeature except that it is designed to be used when the network operator providesdifferent service for different subscribers. Subscribers are classified to be eitherGSM subscribers or MCN (micro cellular network) subscribers. The cells are alsoclassified to GSM cells and MCN cells. Full mobility is provided for GSMsubscribers. The mobility of MCN subscribers is limited and they are allowed toestablish call only in MCN cells. However MCN subscriber can be handed overalso to GSM cell. Subscriber classification is based either on MS powercapability (MS classmark) or defined subscriber priority PIE (priority informationelement).




For more information, see Intelligent Directed Retry in BSC.


7.10 Fixed level adjustment

It is possible to choose a fixed level adjustment in the transcoder in uplink anddownlink directions between +6dB and -6dB with integer intervals.


7.11 Soft comfort noise

When discontinuous transmission is used in an uplink direction and thesubscriber is not speaking, the MS stops transmitting and the transcoder generatessoft comfort noise. When soft comfort noise is used, the subscribers hear that theline is not cut.

Soft comfort noise with DTX saves the battery of the mobile.

In the basic approach presented in Recommendation 06.12 the comfort noise andmore specifically the gain and spectrum of the noise are updated in the receivepart only with 0.5 second intervals, when the update is received from the MS. Asa result, the comfort noise generated in the transcoder can have fast step-wisechanges both in the spectrum and in the volume level. This solution results inabnormal sound that does not resemble very much real background noise. Thesolution is to interpolate the comfort noise parameters obtained from the receivedupdating SID-frame in order to smoothen the comfort noise in the transcoder.This method results in very good comfort noise that resembles very much thenatural background noise.

For more information, see TCSM2 Functionalities.




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7.12 Handling of frames received with errors (handoverimprovement)

This transcoder feature improves the quality of the speech by handling handoversituations better. This method rejects a frame instantly as frame synchronisationerrors are received and uses the old speech parameters, a situation that occurs inalmost all intra-BSC handovers. In more detail, in case of handover a situationoccurs where a TRAU-frame is cut abruptly, and bits from another TRAU-frame(from the target BTS) are read. This results in concatenation of the two fragments.The method detects this situation and the corrupted part of the frame is replacedby the bits from the previous TRAU-frame.


7.13 Bad frame handling improvement (poor fieldimprovement)

This feature improves the quality of the speech by handling better the situationwhere a lot of bad speech frames are received. In Recommendation 06.31 it isstated that: "Whenever a good speech frame is detected, the DTX handler shallpass it directly on to the speech decoder". This is, however, not a very goodsolution for example when the MS is in a weak radio field and individual goodspeech frames are surrounded with bad frames. In this case these good speechframes cause only some arbitrary sounds as they do not contain enoughinformation so that they could be interpreted as speech. It is also more probablethat error detection and correction methods have failed and the frame that hasbeen interpreted as good is actually bad. An improved bad frame handlingmethod is used to prevent short unpleasant sounds. This method works in theuplink direction and it mutes the signal smoothly, if there is evidence of errorsand it also demutes smoothly, once good frames are received again.


7.14 Adaptive gain control/downlink

In a transcoder it is also possible to choose an adaptive gain control in thedownlink direction. In order to have an overall solution to the problems caused bytoo low speech volume in GSM phones and variable volume level in the PSTN ,an adaptive gain has been implemented in the downlink direction to the TRAU toguarantee sufficient volume level in the MS. The gain is attenuated immediately




in steps of 1 dB if any clipping is present in the signal. Clipping is detected byexamining the PCM samples in the transcoder in blocks of 160 samples (20 ms)before conversion from A-law to linear. Full attenuation is reached in 120 ms.This clipping can not be heard as the attenuation is done very fast.

After attenuation, there is a short waiting period after which the amplification isstarted again slowly in 1 dB steps if no clipping is present. The value of thedownlink (DL) gain can vary between 0 dB and 6 dB in TCSM and between 0 dBand 9 dB in TCSM2 and the minimum and maximum limits are adjustable byMMI in steps of 1 dB within this range in the TCSM2. The short waiting period isfive seconds and the interval in 1 dB steps is one second. If there is no speechpresent in the downlink direction then the gain is not increased. Also the shortwaiting period is not updated when there is no speech present. This is done toavoid increasing the amplification in cases when the other party of the telephoneconversation is silent. This may cause amplification of acoustic echo in mobile tomobile calls.


7.15 ETR 09.90 compliance

ETR 09.90 is an ETSI technical report describing changes made in phase 1network for supporting phase 2 mobile stations. The amendments for the phase 1infrastructure are specified in such a way that phase 2 mobile stations obtainacceptable service. For a detailed description of changes, refer to GSMspecification 09.90 .


7.16 SMS-CB DRX

This feature is an enhancement to the Cell Broadcast feature. With the help of itthe MSs are able to receive only the needed part of CBCH , and hence the batteryconsumption decreases.

When the SMS-CB DRX is employed the BSS transmits schedule messages. Aschedule message includes information about the number of immediatelyfollowing consecutive CB messages, planned for that cell. The length of timecovered by the CB messages referred to in a schedule message is called theschedule period of that message. In NTC BSS the length of schedule period isone minute.



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For optimal DRX, a schedule message follows the last message of a scheduleperiod, which is the case in NTC BSS. When no information is known about aCB message, for example, because no schedule message has been receivedreferring to that CB message, an MS reads at least the first block of each CBmessage.

The schedule message contains a message description for each CB message to bebroadcasted during the scheduling period, in order of transmission. The positionof a CB message is called the "message slot number" of the CB message, and itindicates the position of the CB message within the schedule period.

An MS starts working in DRX mode after power up when it has received all themessages of interest sent in the schedule period previous to the current one, andhas received the first schedule message of current period. In this mode the MScan understand from the first block of the schedule message how many newmessages there are, when they will be transmitted, their message identifiers ifthere are less than 6 new messages, and possibly the positions of their repetitions.If the first block indicates that there are no new messages, or sufficiently few sothat their message identifiers and the positions of their repetitions are known, theMS can refrain from reading the other blocks of the schedule message. If there areno new messages at all in the successive scheduling periods, then the MS mayread only the first blocks of the schedule messages.

For more inf ormation, see Cell Broadcast.


7.17 SMS point-to-point

This service provides the means to transfer a short data message from an MS toanother subscriber or from another subscriber to the MS via a store and forwardservice centre. The short message may consist of up to 160 characters. Two typesof short messages are identified: mobile terminating (these are sent from theService Centre to the mobile) and mobile originating (these are sent from an MSto the SC). The short message is transferred on a SDCCH or a SACCH usingSAPI 3 depending on whether a TCH is in use with that MS connection or not,that is, on whether a speech or data call is in progress or not.





7.18 Enhanced Full Rate Codec (ETSI)

Enhanced Full Rate Codec (EFR) is a speech coding algorithm giving a betterspeech quality than the current full rate (FR) coding. Tests indicate that betterquality or comparable to ADPCM could be offered with this codec. This featureuses the state-of-the-art FR traffic channel basis at the speech rate of 13 kbit/s.The major difference between EFR and FR is the speech coding algorithm itself.EFR does not require nor imply support for HR and vice versa. The support forEFR at the BSS can be obtained for a network as any normal SW update. At theA interface new TCSM2 equipment, if not already in use, can be introducedgradually according to needs.

BTS

The Base Transceiver Station (BTS) SW could be upgraded to support Enhancedfull rate speech coding. There is no need for HW upgrades in any generation,which means that the support for EFR is always BTS-specific. The SW upgradedBTSs are capable of supporting Full Rate and Enhanced full rate codingdynamically. Each Radio Timeslot (RTSL) configured to support a FR channelrate can be activated either as a FR or as an EFRTraffic Channel (TCH) on a call.

BSC

EFR could be used even if HR is not in use in the appropriate network. Unlikewith HR only a software update is needed in any existing BSC. Handoversbetween FR and EFR (and vice-versa) are possible, when needed.

The Nokia GSM system has plenty of parameters in the BSS, which have adirect or indirect impact on the speech quality, and the optimisation and fine-tuning of these can be carried out for the network to improve the speech quality.Nokia´s BSC provides a better speech quality during handovers. The channelrate is the primary requirement in assignment and in external handover ifalternatives (For example, channel rate or speech coding) are given. Additionalrequirements are also taken into account in all handovers from TCH to TCH.Such a requirement can be the prohibition of rate changes after first channelallocation. If channel rate or speech codec changes are allowed and a change isneeded because of channel configuration in the BTS, then primarily speechcodecs are changed inside the channel rate and secondarily between channelrates.

The BSC also supports the use of pools, if needed. With pools the BSC makeschecks to ensure that the requirements upon the TCH in question coincide withthe properties of the pool before assignment may continue. The BSC is also ableto handle BTSs supporting and not supporting EFR. This functionality requiresno input from the operator; the BTS capability for EFR is automatically checkedby the BSC when the BTS is being reset. This is important if not all the BTSs



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have been updated to support EFR. It is emphasised that no configuration at theAbis interface is needed for EFR. Any TCH configured to support FR at the Abisinterface can be activated with EFR depending solely on the properties of theBTS. EFR is an optional feature in BSC.

TC

In the Nokia GSM System, the existing FR Transcoder and Submultiplexers(TCSM) can be retained in the network to handle calls made on full rate whileTranscoders Submultiplexers (TCSM2) can be SW upgraded or added to handleextensions and addition of EFR capability.

TCSM2 equipment was originally introduced for HR speech coding purposes.Having Nokia BSS, the MSC shall support circuit pools as specified by ETSI forthe A interface (GSM TS 08.02 and 08.08), if TCSM equipment is meant to beused after support for EFR it is introduced. The same applies to HR. The poolconcept allows the utilisation of remote transcoders with different speech codingcapabilities. If pools are not supported and a speech coding algorithm other thanFR is also supported, then all the existing TCSMs must be replaced withTCSM2s.

TCSM2 equipment allows dynamic switching between different speech codingalgorithms, when configured to support more than one channel rate or speechcoding algorithm. For example, the speech coding for one circuit carrying oneTCH may vary between FR, EFR and HR (as a result of handovers for MS) at theAter interface during one speech call.

MSC

Having Nokia BSS, the MSC shall support circuit pools as specified by ETSI forthe A interface (GSM TS 08.02 and 08.08). The support for EFR in the MSCmainly requires the capability to select appropriate resources based on theinformation received from the MS and relaying that information to the BSS.Since remote transcoders are in use in the Nokia BSS the pool concept shall besupported.

Transmission lines

From the transmission point of view an EFR TCH is like any FR TCH. In NokiaGSM system, the BSS provides flexible transmission solutions and useseffectively the capacity of PCM lines (2Mbit/s). The optimisation of the use of 2Mbit PCM lines can be realised on both, A interface (BSC-MSC) and the Abisinterface (BSC-BTS), thus using the network resources efficiently.




MS

New generation mobile stations (MSs) capable of supporting EFR as defined inthe specification are needed in order to use the feature.

The basic information of a codec type comes from the MSC. The BSC makes thefinal decision about the codec based upon input from the MSC, the BSS speechcodec capabilities and possibly radio channel conditions.

In case of handover the BSC has the option to change the speech codec at thetime of handover. For intra-BSC handover the BSC uses the previously storedinformation from the MSC/VLR about the speech codec preferences in theselection process. BSC forwards the information of codec type to BTS in thechannel activation message. BTS uses this information to configure activatedRTSL to support either conventional full rate codec or EFR. Inband signallingbetween transcoder and BTS is used to control the transcoder codec selection on acall basis.

For more information, see Enhanced Speech Codecs in BSC.


7.19 Enhanced Full Rate Codec (ANSI)

The Enhanced Full Rate Codec (EFR) offers high speech quality to end-users.Tests indicate that better quality or comparable to ADPCM can be offered withthis codec.

From the Air interface dimensioning point of view EFR channels need no specialattention. The same applies to the A-interface because TCSM2 handlesdynamically both FR and EFR coding on the same circuit.

If all the pre-requisites for EFR itself are fulfilled (TCSM2 etc.) then EFR cancoexist with no limitations in the previous HR/FR 'dual-codec' system. That is,the whole BSS supports 'triple codec' approach.

The basic information of a codec type comes from the MSC. The BSC make thefinal decision about the codec based upon input from the MSC, the BSS speechcoder capabilities and possibly radio channel conditions.

In case of handover the BSC has the option to change the speech coder at the timeof handover. For intra-BSC handover the BSC uses the previously storedinformation from the MSC/VLR about the speech coder preferences in theselection process.



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The BSC forwards the information of the codec type to the BTS in a channelactivation message. The BTS uses this information to configure the activatedRTSL to support either conventional full rate codec or EFR. Inband signallingbetween the transcoder and BTS is used to control the transcoder codec selectionon a call basis.


7.20 Cell Broadcast

Short text messages can be broadcasted to all GSM MSs in a specified area.

These messages can be used for informing of PLMN news, emergencies, trafficreports, road accidents, delayed trains, weather reports, theatre programmes,telephone numbers such as the number of Information Bureau or tariffs.

The Cell Broadcast service is characterised by the following aspects:

. No acknowledgement is sent from the MS.

. The cell broadcast message is sent on control channels in a limited area,defined by the originator of the message, by agreement with the PLMN.

. Reception is possible only when the MS is in the idle mode.

. Cell broadcast messages are sent continuously, so that all such messagesare sent in turn, and then repeated. The cycle time needs to be short enoughfor important messages to be received by travellers moving through agroup of cells.

. Cell broadcast messages are mobile terminated only.

. The maximum length of each cell broadcast message is 93 characters. Theconcatenation mechanism allows up to 15 of these 93-character messagesto be treated as segments of a longer message. These segments are thenreferred to as "pages".

. A given message is likely to be received repeatedly, yet the user wants tosee only new messages. A given message is therefore given a updatenumber by the network. If a message with the same geographical scope,message identifier, message code and update number is received earlier, itis clear that this is not new, and is ignored by the MS. If the messageinformation is updated, it has a new update number, so that it is recognisedand received.




Currently the management of CB messages is done either locally or remotelythrough the BSC MMI, 7-bit characters are supported for the CB messages anddifferent messages are identified by serial number.

The new enhancements in Cell Broadcast Service provides both phase 2 andphase 2+ improvements. Phase 2 offers an 8-bit data, whereas phase 2+ (Universal Character Coding2 ) allows a 16 bit representation of user characters.CB messages could be delivered in most of the alphabets or languages around theglobe. Phase 2+ Data coding Scheme also indicates whether text compression isused or not. 41 UCS2 coded characters are included in one CB message pagewithout compression.

User characters can also be input in hexadecimal format in order to supportcharacters which are not reachable by keyboard.

CB messages are stored in BSC in the Cell Broadcast Message File. Once theyare entered in the BSC and activated, they are broadcasted cyclically by the BSCand conveyed transparently through the BTS to the MS.

Capacity

The broadcast area may be as large as a whole PLMN, or as small as a single cell.Typically, a message may take 2 seconds to be transmitted, permitting 60messages to be sent in a period of 2 minutes to that specified broadcast area.

60 different active CB messages per cell can be defined at the most. Themaximum storage capacity is 1280 CB message pages. Multi-page messages upto 15 pages are possible.

For more information, see Cell Broadcast.


7.21 Cell broadcast interface to cell broadcast centre

The Cell Broadcast Centre Interface provides an interconnection between theBSC and Cell Broadcast Centre CBC. The feature provides the service definedfor the CBC-BSC interface (see GSM 03.41 ) and permits open interconnection.For operators it offers centralised means to operate the Cell Broadcast. As avalue-added property the Cell Broadcast Interface provides better tools forrequesting and reporting of the CBCH related loading and especially errorconditions. Also the transmission of each CB message can be requested by the



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CBC. The protocol used between the BSC and the CBC is the XTI-interface. Ituses the services of the OSI Transport Layer. A CBC Application can bedeveloped using XTI Application Programming Interface (X/Open TransportInterface) to interconnect the application to the OSI transport layer.

In the lower layers of OSI the possibilities for the CBC interface are:

. connection through the PSPDN using the AC25-S interface plug-in unit

. connection through PCM/TSL or leased line using AS7-U interface plug-inunit. FE or a router is needed for routing CBC related data and

. connection through LAN using COCEN interface plug-in unit (BSC,BSC2E/2A)

. connection through LAN (BSC2i)

Connection unit in the BSC is OMU. CBC connection shares the same transportmedia as Q3, only a new logical connection is introduced. If a non-redundant Q3connection is used, more transmit capacity can be gained by using a dedicatedplug-in unit for CBC.

For more information, see Cell Broadcast.


7.22 Nokia mPosition" Solution

Mobile Location Services (MLS) are value-added services that integrate a derivedestimate of a mobile terminal's position with other content and information for theend-user. Mobile location services leverage the unique attributes of a mobileservice, providing the user with a timely and highly personalised service thatrelates to their immediate locality. Mobile Location Services offer operators avital service element to enhance existing mobile data service as well as enablenew ones. Mobile Location Services add value to the end-user by improving theirsafety, productivity and quality of information.

MLS as a term encompasses location-based services as well as location-awareservices. Location-based services are those in which the location information ofthe terminal is a fundamental enabler for offering the services. Examples includenavigation, tracking and find-a-friend services. Location-aware services areservices in which the available location information of the terminal will enhancethe usability of existing services, making them more attractive and easy to use.The location information is not a fundamental enabler for offering this kind ofservices. Examples include weather forecast, Restaurant finder, City guide etc.Both types of services can include push and pull delivery.




Improved pinpointing of the end-user's terminal is driven by applications andservices, which enhance the user experience. As the MLS market develops,operators will require an evolutionary solution to provide differentiating servicesto the widest possible subscriber base. This solution will consist of enhancedCell-ID, enhanced-observed timed difference (E-OTD and assisted-globalpositioning system (A-GPS) location technologies complementing each other.

The E-OTD based location services is introduced with BSC S10.5 functionality.A-GPS may be the most accurate positioning method, but the need for bothsoftware and hardware modifications for terminals make it likely that only thehigh-end market segment (for example: smart phones) will use this locationtechnology in the next few years until price levels reach mass marketacceptability. For many MLS, A-GPS accuracy is not yet required by users toenhance their experience of using the service.

The Nokia mPosition Solution offers a comprehensive end-to-end solution formobile location services providing multiple location methods, intelligent locationmiddleware and a wide range of applications.

The mPosition Solution supports a multiple location method environment fromcell accuracy (CI) to improved accuracy (E-OTD) and further to high accuracy(A-GPS) with the flexibility to base investments on the applications offered bythe operator. With these multiple location methods, the operator can support allmobile terminals and users, generating more revenue, reducing costs andguaranteeing a future-proof solution. Furthermore, with the E-OTD positioningmethod, operators not only benefit from better location method accuracy, but alsofrom improved network synchronization and increased capacity from the existingnetwork in the future.

The mPosition solution provides support for different location applications. Thesame location system solution can address the needs of emergency service callers,commercial location-based services and operator services. The system offersinterfaces for internal and external servies and for commercial applications.

The mPosition solution provides standards-based location methods that meet thechallenge of mobile location services in multivendor networks and offer roamingsupport. With standards-based technologies, less integration is required andapplication/service development to APIs is easier, enabling more availableservies.

The mPosition solution provides location-enabling middleware, which meets userrequirements for privacy, security, roaming and profiling functionality.

With Nokia mPosition the mobile operator can build a complete end-to-endsolution for the mobile location services benefiting from Nokia's wide experiencein both handsets and in the networks, as well as systems integration capabilities.



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Nokia mPosition offers operators a modular platform that can be used to provideMobile Location Services to their subscribers. The operator receives thefollowing benefits with Nokia mPosition:

. Portfolio of different positioning methods, depending on the operatornetwork configuration and service offering strategy. Nokia mPositionSolution offers multiple location methods for 2G, GPRS and 3G to supportboth existing and future mobile terminals of all end-users.

. Location middleware enabling effective and innovative use of locationinformation including with privacy, security, roaming and profilingfunctionality.

. A wide range of applications enabling operators to deliver new andexciting services to end users. Access to third party applications isavailable via Nokia TradePoint, which offers a low-cost applicationdistribution channel. Forum Nokia offers an open application developmentenvironment.

Positioning methods supported by Nokia mPosition methods:

. Cell ID (CI) for GSM/ EDGE networks: The CI positioning method usescell/sector identifier (and the coordinates of the cell), to locate mobilestations. The coordinates of the cell can either be the location of the BTS orthe actual center of the cell, depending on the implementation. The CImethod can locate all legacy handsets and it works also in situations wherethere is only one BTS available.

. Cell ID + Timing Advance (CI+TA) for GSM/ EDGE networks: The CI+TA positioning method uses cell/sector identifier (and the coordinates ofthe cell) and Timing Advance (TA) to locate mobile stations. CI+TA canlocate all legacy handsets and it works also in situations where there is onlyone BTS available.

. Cell ID, Timing Advance and Received Signal Strength (CI+TA+RX) forGSM/ EDGE networks: The CI+TA+RX positioning method uses cell/sector identifier (and the coordinates of the cell), Timing Advance (TA),and Received Signal Strength (Rx level) to locate mobile stations. CI+TA+RX can locate all legacy handsets and it works also in situations wherethere is only one BTS available.




. Enhanced Observed Time Difference (E-OTD) for GSM/ EDGE networks:The E-OTD method requires an E-OTD enabled mobile station andrequires that the MS receives a signal from at least three base stations: theserving base station and two neighbouring base stations. The coordinatesof each base station in the network are known.

. Assisted Global Positioning Systems (GPS) for GSM/ EDGE networks: Inassisted GPS, the SMLC requests location estimation from the target MSand sends GPS assistance data to the MS.

Nokia mPosition system overview

The Nokia mPosition Solution offers a comprehensive end-to-end solution formobile location services providing multiple location methods, intelligent locationmiddleware and a wide range of applications.

The Nokia intelligent Gateway Mobile Location Center (iGMLC) enablesexternal applications and servers to access the location information of mobilestations in the telecom network. In addition, the optional GMLC PrivacyManager provides subscribers with a wide range of options to explicitly defineprivacy policies. This feature allows the subscriber to decide how, when, and towhom personal location data is given.

Nokia's iGMLC provides more functionality than the 3GPP standard GMLC. Theadded functionality includes optional Presence and Privacy Manager features.

The Mobile Switching Center/Visitor Location Register (MSC/VLR) isresponsible for mobile subscriber authorisation and managing call-related andnon-call related location requests.

The Home Location Register (HLR) contains location services subscription dataand routing information that allows the location request to reach the mobilesubscriber.

The Base Station Controller (BSC) coordinates and schedules all resourcesrequired to locate the mobile subscriber and receives location data from themobile station.

The Base Transceiver Station (BTS) measures and transfers data that will be usedin location calculations. In mPosition for E-OTD networks, it serves as the relayelement between the Location Measurement unit (LMU) and the BSC.

The Location Measurement Unit (LMU), which is only required in the mPositionfor E-OTD solution, makes radio interface timing (RIT) measurements for E-OTD and can be used for BSS synchronisation.



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The stand alone Serving Mobile Location Center (SMLC) is used in themPosition for Legacy Phones solution to combine network data exported from aradio network planner with real-time location requests from GMLC to calculatethe latitude and longitude of the mobile subscriber. In the mPosition for E-OTDsolution, the SMLC is integrated into the BSC.

For more information, see Location Services.


7.23 Wireless Priority Service in BSC

The Wireless Priority Service (WPS) feature is implemented in S10.5. The featurewas developed according to the US government requirement.

WPS allows qualified and authorized National Security and EmergencyPreparedness (NS/EP) users to obtain priority access to radio traffic channelsduring situations when Commercial Mobile Radio Service (CMRS) networkcongestion is blocking call attempts.

The WPS is an optional feature in the BSC.

Note

The WPS feature is applicable only in ANSI environment.

Note

The use of WPS IOC SOFTWARE is restricted in the U.S. and U.S.TERRITORIES to NS/EP users authorized by the Office of the Manager,National Communication System (OMNCS). ELIGIBLE CMRS PROVIDERdeployment of these WPS IOC SOFTWARE must be coordinated with theOMNCS at the following address:

Office of the Manager

National Communications System

Attn: GETS Program Office

701 South Courthouse Rd.




Arlington, VA 22204-2198

Email: [email protected]

For more information on the feature, see Wireless Priority Service in BSC.

7.24 Text Telephony (TTY)

Hearing impaired and speech impaired persons have been using specific TextTelephone (referred to as TTY) equipment in the fixed network for many years totransmit text and speech through ordinary speech traffic channels. Modern digitalcellular systems, however, do not provide satisfactory character error rates for texttransmitted in the speech channel with the traditional modulation developed forthe fixed network.

TTY phones enable people with hearing disability or speech impairment tocommunicate over conventional telephone lines using text messages. There aretwo types of text telephones: TTY (TeleType) and TDD (TelecommunicationsDevice for the Deaf). TTYs are basically mechanical teleprinters and TDDs aretheir electronic counterparts. Virtually all text telephones support "5-bitoperational mode" using Baudot code.

The GSM1900 Standards Body, T1P1, has selected and recommended CellularText Telephone Modem (CTM) solution to improve TTY/TDD signaling. Thissolution employs a modulation technique that passes through the speech codecwith less distortion and includes error protection, interleaving, andsynchronisation.

In Nokia's implementation TTY functionality is done for TCSM2 by softwareupdate on top of S10.




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8 BSS10, BSS10.5 and BSS10.5 EDdependencies

The BSS10, BSS10.5 and BSS10.5 ED dependency tables below indicate thedependencies of S10, S10.5 and S10.5 ED features with the existing hardwareand software.

The dependence tables of the previous releases can be found, for example, inBSS8 Existing Features and BSS9 Existing Features documents.

In the tables the following notations are used:

GSM 800. This feature is supported in the GSM/EDGE 800 MHz system (Y=yes, N= no).




MSC. This feature is supported in the Nokia MSC (xxx = Nokia MSC release/feature nbr., N= no, - = not applicable).

Nokia NetAct. This feature is supported in the Nokia NetAct (Y= yes, xxx =Nokia NetAct release/feature nbr., - = not applicable).

BSC. This feature is supported by the BSC (Y= yes, N= no). (Y) in parenthesesindicates that the BSC is not actually applicable with this feature.

SGSN. This feature is supported by the SGSN (Y= yes, N= no). (Y) inparentheses indicates that the SGSN is not actually applicable with this feature.



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Nokia NetAct Planner. This feature is supported in Nokia NetAct Planner, (Y=yes, xxx = Nokia Totem Access release/feature nbr., - = not applicable).

Nokia 2nd Gen. This feature is supported by the 2nd gen. BTS (Y= yes, N= no).(Y) in parentheses indicates that the BTS is not actually applicable with thisfeature.

Nokia Talk-family. This feature is supported by Nokia Talk-family of basestations (Y= yes, N= no). (Y) in parentheses indicates that the BTS is not actuallyapplicable with this feature.

Nokia PrimeSite. This feature is supported by Nokia PrimeSite (Y= yes, N= no).(Y) in parentheses indicates that the BTS is not actually applicable with thisfeature.

Nokia MetroSite. This feature is supported by Nokia MetroSite (Y= yes, N= no).(Y) in parentheses indicates that the BTS is not actually applicable with thisfeature.

Nokia InSite. This feature is supported by Nokia InSite (Y= yes, N= no). (Y) inparentheses indicates that the BTS is not actually applicable with this feature.

Nokia UltraSite. This feature is supported by Nokia UltraSite (Y= yes, N= no).(Y) in parentheses indicates that the BTS is not actually applicable with thisfeature.

BSC MMI. This feature has parameters that are managed with the BSC MMI(Y= yes, - = not applicable).

BTS MMI. This feature has parameters that are managed with the BTS MMI (Y=yes, - = not applicable).

MS. The feature sets special requirements to mobile stations (Y = yes, see thenote; - = no requirements).

BSC HW/FW. This feature requires additional or alternative BSC hardware orfirmware (Y= additional, A= alternative, or - = not applicable).

BTS HW/FW. This feature requires additional or alternative BTS hardware orfirmware (Y= additional, A= alternative, or - = not applicable).

TC HW/FW. This feature requires additional or alternative transcoder hardwareor firmware (Y= additional, A= alternative, or - = not applicable).

SGSN HW/FW. This feature requires additional or alternative SGSN hardware orfirmware (Y= additional, A= alternative, or - = not applicable).




STD/ OPT. Indicates whether this feature is an optional or a standard BSS feature(S = standard, O = optional).

SW Support for AFC

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

N Y N N � � (S10) �

NokiaNetActPlanner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltraSite

� N DF6 N N N N

BSCMMI BTSMMI MS BSCHW/FW

BTSHW/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

� � � � Y � � S

TRX monitoring by RSSI

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

N Y Y Y � � (S10) N

NetActPlanner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

Nokia-Metro-Site

NokiaInSite

NokiaUltraSite

� N DF6 N N N N



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BSC-MMI

BTSM-MI

MS BSCHW/FW

BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

� Y � � � � � S

Rx Antenna Supervision by Comparing RSSI Value for Nokia UltraSite

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � � (S9) �

NetActPlanner

Nokia2ndGen.

NokiaTalk-family

Nokia-Prime-Site

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

� (B12) (DF5) (DF5) N N CX3.0


BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

Y Y � � � � � S

Automated Planning

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � OSS3.1 S10 �

NetActPlanner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

� (B12) (DF5) (DF5) (CX2) (I2) (PU1)





BTSHW/FW

TCHW/FW

SGS-NHW/FW

STD/OPT

Y � � � � � � 0(*)

(*) Nokia NetAct optionality

Synchronised BSS

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � OSS3.1 S10 �

NetActPlan-ner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

� N DF6(*) N N N CX3.0

BSCMMI BTSMMI MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

Y � � � Y(**) � � S

(*) FlexiTalk BTS does not support this feature.

(**) Additional BTS hardware required (LMU)

Double Mobile Allocation (MA) list amount

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � OSS3.1 S10 �



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NetActPlan-ner

Nokia2ndGen.

Nokia-Talk-family

Nokia-Prime-Site

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

� (B12) (DF5) (DF5) (CX2) (I2) (PU1)

BSC-MMI

BTSM-MI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSNH-W/FW

STD/OPT

Y � � � � � � S

FER Measurement

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � OSS3.1 S10 �

Ne-tActPlan-ner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

� N DF6 DF6 CXM3.0 N CX3.0

BSC-MMI

BTSM-MI

MS BSCHW/FW

BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

Y � � � � � � S

Adaptive Multi Rate Codec, AMR

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y M10 OSS3.1 S10 �




NetActPlan-ner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

� N DF6 DF6(*) CXM3.0 N CXM3.0

BSC-MMI

BTSM-MI

MS BSCH-W/FW

BTSHW/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

Y � Y(**) � � A(***) � O

(*) FH is removed if AMR is implemented.

(**) AMR capable MS required.

(***) TCSM2 with new pools required.

Nokia Smart Radio Concept for EDGE (Nokia SRC)

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � � S10 �

Ne-tActPlan-ner

Nokia2nd Gen.

Nokia-Talk-family

NokiaPri-meSite

Nokia-MetroSite

NokiaInSite

NokiaUltraSite

Plan-ner 4

N N N N N CX3.0

BSC-MMI

BTS-MMI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSNH-W/FW

STD/OPT

� Y � � Y � � S(*



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(*) EDGE HW required.

Multi BCF Control

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � OSS3.1(***)

S10.5 �

NetActPlan-ner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

Plan-ner 4

N DF6 (**) N N N CX3.0

BSC-MMI

BTS-MMI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

Y � � � Y � � S(*)

(*) Works within same frequency band. Common BCCH feature needed for multiband single cell solutions.

(**) FlexiTalk BTS does not support this feature.

(***) OSS3.1 ED1

Support of PCCCH/PBCCH

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y M11 OSS3.1(**)

S10.5 SG2




NetActPlan-ner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

Plan-ner 3.4

B13 DF6 DF6 CXM3.0 N CX3.0

BSC-MMI

BTS-MMI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

Y � Y(*) � � � � S

(*) (E)GPRS capable terminals.

(**) OSS3.1 ED1 (Enhancement Delivery).

Priority Class based Quality of Service

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y M11 OSS3.1(**)

S10.5 SG2

NetActPlan-ner

Nokia2ndGen.

Nokia-Talk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

� (B12) (DF5) (DF5) (CX2) (I2) (PU1)

BSC-MMI

BTS-MMI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

Y � Y(*) � � � � S




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(**) OSS3.1 ED1.

System Level Trace

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y M11 OSS3.1(**)

S10.5 SG2

NetActPlan-ner

Nokia2nd Gen.

Nokia-Talk-family

NokiaPri-meSite

Nokia-Metro-Site

NokiaInSite

NokiaUltraSite

� (B12) (DF5) (DF5) (CX2) (I2) (PU1)

BSCM-MI

BTSM-MI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSNH-W/FW

STD/OPT

� � Y(*) � � � � S


(**) OSS3.1 ED2.

Tri Band - Common BCCH

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y N � OSS3.1(**)

S10 �

NetActPlanner

Nokia 2ndGen.

NokiaTalk-family

NokiaPri-meSite

NokiaMe-troSite

NokiaInSite

NokiaUltraSite

4.0 N DF6 N CXM3.0 N CX3.0




BSCM-MI

BTSM-MI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSNH-W/FW

STD/OPT

Y � Y(*) � � � � O

(*) Multi band capable terminals.

(**) OSS3.1 ED1.

Chaining of Nokia MetroSite Base Station

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � (T12) (S9) (SG1)

NetActPlanner

Nokia 2ndGen.

NokiaTalk-family

NokiaPri-meSite

Nokia-Metro-Site

NokiaInSite

NokiaUltraSite

� N N N CXM3.0 N N

BSC-MMI

BTSM-MI

MS BSCH-W/FW

BTSH-W/FW

TCHW/FW

SGSN-HW/FW

STD/OPT

� Y � � Y(*) � � S

(*) Extension cable between cabinets.

Nokia mPosition" rel 2.0 Location Services for E-OTD phones

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y M10 T12(***)

S10 �



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NetActPlanner

Nokia 2ndGen.

NokiaTalk-family

Nokia-Prime-Site

NokiaMetroSite

NokiaInSite

NokiaUltraSite

TotemV

B13 DF6 DF6 CXM3.0 N CX3.0

BSC-MMI

BTSM-MI

MS BSCHW/FW

BTSHW/FW

TCHW/FW

SGSNHW/FW

STD/OPT

Y Y(*) Y(**) Y � � O

(*) E-OTD and GPS require mobile support.

(**) Mandatory SMLC (CP6MX card) upgrade for field BSCs and MBIF-UAupgrades for BSCE and BSC2E/A models in OMU, MCMUs and BCSUs units.

(***) T12 FN (Functionality Note).

Enhanced Data Rates for Global Evolution, EDGE

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y M10 OSS3.1(****)

S10.5 SG2

NetActPlan-ner

Nokia2nd Gen.

NokiaTalk-family

NokiaPrimeSite

NokiaMetroSite

NokiaInSite

NokiaUltraSite

Plan-ner 4

N N N CXM3.0 N CX3.0




BSCMMI

BTS-MMI

MS BSCHW/FW

BTS HW/FW

TC HW/FW

SGSNHW/FW

STD/OPT

Y � Y(*) Y(**) A(***) � � O

(*) EDGE capable mobiles.

(**) In BSC2E/A and BSC2i Optional PCU, Packet Control Units (1+8->2+16)and GSWB (192->256) extensions and ETs can be extended (112->144 E1/T1s),BSC2E and BSCi do not support 2nd PCUs in BSS10 or BSS10.5. BSCi supportfor 2nd PCU is under further study.

(***) New EDGE capable transceiver.

(****) OSS3.1 ED1 (Enhancement Delivery).

GSM-WCDMA Inter-System Handover

GS-M800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y M11 OSS3.12)

S10.5 �

NetActPlan-ner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltraSite

BSCMMI

Plan-ner V

B13 DF6 DF6 CXM3.0 I3 CX3.0 Y

BTSM-MI

MS BSCHW/FW

BTSHW/FW

TCHW/FW

SGSNHW/FW

STD/OPT

� Y 1) � � � � O 2)

1) Dual mode (GSM-WCDMA) MS(UE). 2) OSS3.1 ED (EnhancementDelivery). 3) WCDMA RAN and GSM BSS optionality.



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Dynamic Abis Allocation

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � OSS3.12)

S10.5ED

�

NetAct-Planner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltraSite

BSCMMI

Planner4

N N N CXM3.0 N CX3.0 �

BTSMMI

MS BSCHW/FW

BTSHW/FW

TC HW/FW

SGSNHW/FW

STD/OPT

� � � A 1) � � O 3)

1) EDGE capable TRX; 2) OSS3.1 ED (Enhancement Delivery). 3) DynamicAbis is part of EDGE optionality

GSM/EDGE 800/1900 Dual Band

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y N N Y � OS-S3.1 3)

S10.5 �

NetActPlanner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltra-Site

BSCMMI

PlannerV

N N N (CX-M3.0)

N (C-X3.0)

Y




BTSM-MI

MS BSC HW/FW

BTS HW/FW

TC HW/FW

SGSNHW/FW

STD/OPT

� Y 1) � A � � O

1) Multi band GSM800/1900 capable terminals. 2) GSM800/1900 HW. 3)OSS3.1 ED (Enhancement Delivery)

Common BCCH Control

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y N N Y � OSS3.1**)

S10.5 �

NetAct-Plan-ner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltra-Site

BSCMMI

Plan-ner V

N N N (CX-M3.0)

N (C-X3.0)

Y

BTSM-MI

MS BSCHW/FW

BTSHW/FW

TC HW/FW

SGSNHW/FW

STD/OPT

� Y *) � A � � O

(*) Multi band GSM 800 / 1900 capable terminals.

(**) GSM 800 / 1900 HW.

Text Telephony (TTY)

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � � S10 �



263 (266)


NetAct-Plan-ner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltra-Site

BSCMMI

� (B12) (DF5) (DF5) (CX2)) (I2) (PU1) Y

BTSM-MI

MS BSCHW/FW

BTSHW/FW

TC HW/FW

SGSNHW/FW

STD/OPT

N Y(*) � � � � S

(*) TTY modems.

Wireless Priority Service in BSC

GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y N N Y M11 � S10.5(*)

�

NetAct-Plan-ner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltra-Site

BSCMMI

� (Y) (Y) (Y) (Y) (Y) (Y) �

BTSM-MI

MS BSCHW/FW

BTSHW/FW

TC HW/FW

SGSNHW/FW

STD/OPT

� � � � � � O

(*) S10.5 CD

Nokia Power System Management (PSM) Enhancements




GSM800

GSM900

GSM1800

GSM1900

MSC NokiaNetAct

BSC SGSN

Y Y Y Y � OSS3.1(*)

(S9) �

NetAct-Plan-ner

Nokia2ndGen.

NokiaTalk-family

NokiaPrime-Site

NokiaMetro-Site

NokiaInSite

NokiaUltra-Site

BSCMMI

� � Y � � � Y �

BTSM-MI

MS BSCHW/FW

BTSHW/FW

TC HW/FW

SGSNHW/FW

STD/OPT

� � � A (**) � � O (***)

(*) OSS3.1ED

(**) ) Nokia Battery Back Up/ Site Support System

(***) AUX option



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nokia gsm_edge feature description bsss10.5ed

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